Child Study Center Grand Rounds 01.26.2021

March 23, 2021

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Beyond Goon Park What Rhesus Monkeys Reveal About the Intergenerational Effects of Secure Attachment

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00:00I'm so excited to share with you the
00:03body of work I've been engaged in with
00:06primates for really over the last 20 years,
00:09so please bear with me for one moment while
00:12I finalize my screen sharing and I just
00:15need to click a few more buttons here.
00:18So please enjoy this lovely photo of
00:20a monkey, Mother, infant and mom.
00:27OK.
00:43Great.
00:46So I'm so excited to talk today about
00:48the intergenerational effects of secure
00:50attachment in rhesus monkeys and what we
00:52can learn from studying primate models.
00:55But first, before I get into that
00:57work and the work that led to it,
01:00I think it's really important to put this
01:02body of research into context and to do that,
01:05we're going to start at Green Park.
01:08Probably many of you are wondering
01:10what the heck is going park.
01:12Hogan Park was the name of the psychology
01:15Department at University of Wisconsin,
01:17Madison and its street address
01:19was actually 600 N Park Ave.
01:21But when people would quickly scrawl the
01:23address back in the middle of the last
01:26century early last century, you know,
01:29for intercampus Mail they would write
01:31600 and Park Anna sloppy handwriting.
01:33It looks like Goon Park and the nickname
01:36just stuck and so even though the building
01:38has long since been demolished and renovated,
01:41the address.
01:42Is still the same and good park is
01:45important because it sets the stage for
01:47the work that will be talking about today.
01:51It's also the location for this
01:53fabulous book which I recommend to
01:55everybody here called Love at Goon Park.
01:57Written by Pulitzer Prize winning
01:59journalist and science writer
02:01extraordinaire Deborah Blum,
02:02here's a little bit about that book for Eons,
02:05Love was the province of poets and Dreamers.
02:08Scientists considered it unworthy
02:09of real study,
02:10yet in the middle of the last century,
02:13one scientist had the courage.
02:15And the curiosity to uncover
02:17the true power of love.
02:19And he forever changed the way we
02:21think about human relationships.
02:22This is the story of that
02:24great transformation.
02:25And in fact,
02:26that one human whom she
02:28writes about was Harry Harlow.
02:30Now, although he died almost 40 years ago,
02:33Harry Harlow had a lasting
02:35impact on the science.
02:36We do the treatments we give to children,
02:39and most importantly,
02:40what we know to be true
02:43about children's needs.
02:44Now Harlow is best known for his now
02:48controversial studies on maternal separation,
02:50like social isolation Ring,
02:52which is depicted here in which
02:54infant monkeys would be reared
02:56in complete total isolation.
02:58No visual, auditory,
03:00or tactile access to any other animals
03:03for periods ranging up to 12 months.
03:06These studies actually followed
03:07his very earliest studies,
03:09which he's also known for into attachment
03:12by studying monkeys on attachments too.
03:15Inanimate surrogate mothers
03:16covered in a soft fuzzy cloth.
03:19Ann,
03:19it's important to know that these studies
03:22were not so controversial at the time.
03:24In the 1950s and 60s,
03:26because but they are now and the
03:28reason for that is that we need to
03:31recognize that scientific standards
03:33change overtime as we gain knowledge
03:35an this includes the ethical standards.
03:37Now, for a look into how ethical standards,
03:40and also oversight, has changed.
03:42I mean, just take a look at that PPE right?
03:46He's not wearing any,
03:47and there's no way it that.
03:49Anybody now could walk up to
03:51any monkey in it
03:53in their street clothes?
03:54So not only has PPE standards change,
03:57but the way we treat the animals that
04:00we work with and the types of research
04:02that we can do have evolved overtime.
04:05And in fact there is very strict
04:07oversight at multiple levels.
04:09Anybody conducting monkey research
04:10has to adhere by law by federal
04:13law to institutional oversight and
04:15multiple levels of federal oversight.
04:17And so, along with the change
04:20in ethical standards,
04:21the science has changed as well.
04:23Now most people don't know that
04:26for several decades before his
04:27experimental work into attachment,
04:29Harlow actually studied learning cognition.
04:31An even neural function in monkeys.
04:34So for the first few decades of his
04:37careeer working first at a nearby zoo,
04:40but then developing his own lab,
04:42he studied cognitive abilities in primates,
04:45and he discovered that monkeys were far
04:48more cognitively complex than rats were.
04:50Again,
04:50we didn't know that at the time and
04:52they could form complex learning
04:55and problem solving strategies.
04:56That is,
04:57they could learn to learn and the
04:59way he devised this information
05:01is by developing a Now classic
05:03apparatus at least classic,
05:05to cognitive psychologists and
05:07comparative psychologists called
05:08the Wisconsin General Testing
05:09apparatus depicted here on the left,
05:11or the WDT,
05:12and this is important because it's
05:14going to make an appearance later,
05:17so Harlow and discovering how
05:18smart monkeys were.
05:20He wanted to study the ontogeny of learning.
05:23So to do this,
05:23he needed easy access to infant monkeys,
05:25so he started a nursery.
05:28And he observed that during the routine
05:30care and cleaning up these nursery
05:32monkeys where they had cloth diapers
05:34lining the bottoms of their cages.
05:36Whenever the diapers were removed,
05:37the infants would throw major
05:39tantrums and would only be sued
05:41when a new cloth diaper was put in.
05:43And so he thought.
05:44Could these monkeys be attached
05:46to their cloth diapers?
05:47And this in fact led to his series
05:50of studies in the next several
05:52decades for the rest of his
05:54career into affectional systems.
05:56Now it's impossible to overstate
05:58just how much we now take for
06:00granted that it is normal, natural,
06:02and necessary to touch and hug and
06:04hold our children and to nurture them,
06:06and not just for moms to do it,
06:09but for dads to do it too,
06:11and not just to do this in infancy,
06:13but across their whole lives,
06:15and not just to do it when
06:17they're behaving well,
06:18but maybe most importantly,
06:19when they are upset and need need that
06:22comfort most like you can see in this
06:24final picture here in the bottom right,
06:26where my husband is comforting her son.
06:28Sorry,
06:29the day we had to Bury our cat.
06:31It was emotional for all of us.
06:34So we take this for granted now,
06:36and it's because of Harlow's work
06:37that we now can take this for granted.
06:40And his work has also laid the
06:42foundation for the treatments we give.
06:44For example,
06:45to infants in the Nick you for the
06:47breast feeding practices,
06:48and also again for the ways that
06:50we care for children across their
06:52life spans and across generations.
06:55As I said, this was not always the
06:57document in the mid 20th century.
07:00Common dogma was that too much physical
07:02contact with children would make them weak,
07:05both physically via exposure
07:06to germs and psychologically.
07:08And you can see this quote from
07:10one of the fathers of behaviorism.
07:12In his book on Infant Child Care,
07:15you will soon be ashamed of
07:17the mawkish sentimental way you
07:18have been handling your child.
07:20Well, Harlow disagreed and based on
07:23what he observed in his infant monkeys.
07:26He stated in his first presentation
07:27of these findings to the American
07:29Psychological Association
07:30presidential address.
07:31He boldly stated there is more to mother.
07:34There is more to Mother love than milk,
07:37and that's perfectly
07:38illustrated by this image here,
07:39in which the infant monkey is maintaining
07:42as much physical contact as possible
07:44with a soft cloth surrogate mother
07:46and stretching over to drink from the
07:48bottle that's attached to the wire mother.
07:51And in fact,
07:52he also discovered that monkeys
07:54would learn to open windows just
07:56to get glimpses of their.
07:57Soft cloth covers.
07:59Surrogate mother.
08:01And so his studies really
08:03revolutionized the scientific thinking
08:05about socialization processes.
08:07Now around the same time,
08:09someone else was getting into attachment,
08:12and we're probably all very familiar
08:14with this father of attachment theory.
08:17British psychologist John Bowlby.
08:19I really hope that anyone here who works
08:22with children is familiar with John
08:24Bowlby's early theories of attachment,
08:26which also changed the way
08:28we think about children.
08:29However, Bowlby knew of no
08:31experiments that manipulated the
08:32potentially relevant variables in
08:34the domain of attachment formation,
08:35and that is to say he knew of no
08:39science to support his theories.
08:42Well, Fortunately enough,
08:43and this is something interesting
08:45I discovered in the research
08:47for this presentation.
08:48Turns out boldly in Harlem became
08:50friends and I really want to
08:52encourage everyone point you to
08:54this fascinating historical article.
08:56I love you Tana that talks about and
08:59really goes into detail about their
09:01professional correspondence that
09:02evolved giver, hug and kiss for me.
09:05OK,
09:06dad and collaboration give her
09:08a hug and kiss from.
09:15Amanda, can you unmute yourself? Sorry.
09:23OK, that's better.
09:24OK, so their correspondent started in
09:271957 and in one of the first response is
09:30that Harry Harlow gave to John Bowlby,
09:32which is almost exactly 63 years
09:35ago to the day. Harlow rotable be.
09:38It's an understatement.
09:39To add that we have research interests
09:41in common and from this point forward,
09:43the two greatly influenced each other's work.
09:45Bowlby sent Harlow, for example,
09:46a draft paper for which he would be
09:48most grateful for any comments and
09:50criticisms that Harlow care to make.
09:52What was the name of that paper?
09:54Well, it was his first draft of the
09:56nature of the child's tide to its mother,
09:59which he published in 19.
10:0058 and Harlow would refer to this
10:02paper as the reference Bible.
10:07And so, over the years,
10:09hard over the next several years,
10:12Harlows work his empirical findings on
10:14maternal separation provided Bowlby with
10:16evidence that he needed for his own knew
10:19conceptualisation of separation anxiety
10:21as a survival mechanism for infants,
10:23and particularly of the mother or
10:26caregiver as a haven of safety with
10:28a term which Harlow would use in
10:31subsequent publications or what
10:33we now call a secure base.
10:36And so if it's true that John Bowlby is
10:38considered the father of attachment theory,
10:40then I think it's only fair to consider Harry
10:44Harlow the father of attachment science.
10:47And Harlow intern.
10:48This relationship was bidirectional
10:50Harlow Internews Bowlby's theories
10:52and his inspiration for the design
10:55of his studies to systematically
10:57test the effects of maternal infant
10:59separation on infant development.
11:01And it's really important to note
11:04Bowlby's influence on comparative
11:06psychology and animal research as a field,
11:09and these are just some of the three major
11:12ways that his thinking influenced our work.
11:20So Harlow then from that point on
11:23made a career of using rhesus monkeys
11:25to study things that were not easily
11:28researched in humans themselves.
11:31He studied the consequences of blocking
11:33the formation of different affectional
11:35systems via isolation rearing,
11:37which I also mentioned,
11:38or which I mentioned earlier,
11:41affectively reproducing psychopathologies
11:42in monkeys that are observable in humans,
11:45namely severe depression,
11:46and these are the controversial
11:48studies that he's most.
11:50Well known for, but it's really important.
11:52This is not all that he focused on,
11:54because later in his career he also
11:57studied the importance of other social
11:59relationships and so with his second wife,
12:01Margaret Harlow,
12:02who developed this really cool apparatus
12:03called nuclear family housing,
12:05in which adults and infants lived
12:07in separate apartments here.
12:08But the adults were confined
12:10to their apartments.
12:11Both the mother and the father
12:12and the infants could go through
12:14this tunnel and play with each
12:16other at will throughout the day.
12:18But at night they would be locked in at home,
12:21in their apartments with each other.
12:24And in this way he could
12:26systematically study the you know,
12:27by manipulating the amount of time that
12:30infants had exposure to each other.
12:32He could study the impacts of peer
12:35relationships on infant development.
12:37And so this whole body of work
12:39started to definitively establish
12:40the overwhelming importance of early
12:43social experiences for the development
12:45of normal behaviors later in life.
12:50And beyond establishing that human
12:52psychopathologies can be reproduced
12:54in primates and that various
12:56social experiences are normal or
12:57important for normal development,
12:59unbeknownst to many,
13:00Harlow also focused on therapeutics,
13:02and one such example are the series
13:05of studies that he and his colleagues
13:08conducted rescuing the social behavior
13:10of those isolates I mentioned earlier,
13:13and so they achieve this through
13:15peer therapy sessions. And So what?
13:18You're looking at the top here is.
13:21On a social isolate,
13:22who until this time had never
13:25been exposed to another monkey,
13:27very clearly very anxious and withdrawn
13:30Hereupon initial contact with another infant.
13:32And importantly, the infants were younger
13:35than the social isolates themselves,
13:37and after several months of a
13:40carefully controlled exposure,
13:41everyday to these peers,
13:43the isolates then went on to develop
13:46pretty typical social behaviors.
13:48And so this whole body of work,
13:51very fondly referred to this
13:53research trilogy as Love, created,
13:54love, destroyed, and Love regained.
13:56And this may sound rather poetic.
13:59And in fact,
14:00Harlow was really a poetic writer.
14:02He actually had a speech
14:04impediment as a child,
14:05and through many years of teaching
14:07as a professor, he overcame that,
14:10and he turned into a prolific and poetic
14:12science communicator whose sense of
14:14humor carried over into his writing,
14:17and let me tell you,
14:19Harlow was.
14:19Hilarious,
14:20so I also stumbled upon in the background
14:22research for this presentation.
14:24This article by Harlow comparing different
14:27cognitive abilities of primates in the
14:29early zoos that he worked in in in Wisconsin.
14:31Now you might notice the publication
14:34date 2008,
14:34but he died in the 80s,
14:36so actually this was published posthumously.
14:38It was found in his archives,
14:41an article he had never published.
14:43An was published in 2008,
14:44so I want to give you a little glimpse
14:47of how he could both entertain.
14:50While educating his audience,
14:51the performance of the two chimpanzees was
14:54no better than the best of The Monkees.
14:56Furthermore,
14:56the chimpanzees never seemed to
14:58really get down to work and put their
15:00hearts into psychological testing.
15:02At the time we attributed their good
15:04natured distract ability to their
15:06age instead of the obvious answer.
15:07The fact that they were chimpanzees.
15:11And then here's one more which
15:13really starts to explain why rhesus
15:15monkeys are such a superior model.
15:17The rhesus monkey lacks the gay
15:19abandoned of the cebus monkey,
15:21the elegant grace and composure
15:22of the spider,
15:23or the buffoonery of the chimpanzee.
15:25But beneath the Gray or grim
15:27exterior of the recess is a central
15:30nervous system waiting to grind
15:31out 100 test trials of day.
15:33The difference between a cebus
15:35monkey and a Reese's is all the
15:37difference between a southern Belle
15:39Anna New England storekeeper.
15:40Our primary interest,
15:42concerned learning and intelligence.
15:43So those are just some examples of
15:46the types of writing that I wish
15:48we saw more of today and beyond
15:50explaining some of the reasons why
15:53rhesus monkeys were great models.
15:55We now know even more why there,
15:57why there's such reliable
15:59models for the study of humans.
16:02One reason is that rhesus
16:03macaques second only to humans,
16:05are second only to humans in
16:07their geographic distribution.
16:08So there's the second most widely
16:10distributed primate in the world,
16:12and you could see their
16:14distribution here on this map.
16:18Rhesus macaque San humans also share
16:20a high degree of genetic similarity,
16:23about 93%, and in fact there are
16:26some polymorphisms that are unique
16:28only to humans and rhesus macaques.
16:33Another limiting factor in human studies is
16:35a very long life span that humans have now.
16:39This makes it really difficult to study
16:41the same people continuously across the
16:43lifespan and to get repeated sampling.
16:46Whether it's biological
16:47or behavioral measures.
16:48But rhesus monkeys develop approximately
16:504 times faster than humans,
16:52and so this makes the study of life
16:54course an intergenerational studies
16:55possible in a shorter time frame.
16:58And the monkeys I'm showing you here
17:00are some of my absolute favorites.
17:03From my work in Maryland,
17:05this is my very favorite monkey
17:06mom of all time, Xena,
17:08with her infant Zinnia in 2008 and
17:10just six years later as India had
17:12her own first infant named Rufus.
17:14And so we were able to study this whole
17:17family together within just a few years time.
17:20And as mentioned earlier,
17:22nonhuman primates,
17:23particularly macaques,
17:24have complex cognitive abilities as well
17:27as very complex social behavioral repertoire,
17:31which are,
17:32which are made possible due to their nerdy
17:36nuro anatomical similarities to humans.
17:40So Harlow's legacy was really far
17:43reaching and it still is to this day
17:46his research has provided an enduring
17:48empirical foundation for future work
17:50because of his foundational studies
17:53into the formation of attachment.
17:55We now as scientists can study the
17:58interactions of childhood experiences,
18:00genetics, biological factors,
18:01and epigenetics just to give some examples.
18:05We're also able and wanting to study
18:07the vulnerability of children or their
18:10resilience and recovery in various
18:12health outcomes across the lifespan,
18:14and scientists today can answer
18:16questions that Harlow could not,
18:18because since his foundational studies,
18:20we've seen an evolution and such
18:23techniques like a neuroimaging
18:25and epigenetics research.
18:27An his legacy of knowledge.
18:31Really illustrate is really illustrated
18:33here in this graphic that shows
18:36just how far reaching his work is.
18:38He's had over 10,000 citations of
18:41his work and almost 7000 articles,
18:43and you can see the disciplines that
18:46his work are cited in here and some
18:48of the more interesting or obscur
18:51ones include educational research,
18:53endocrinology, and metabolism,
18:54general internal medicine among others,
18:56and so this is really a testament
18:59to how science continues to build
19:01upon understanding.
19:02Formed in the past.
19:06Now Harry's legacy, of course,
19:08was embodied in his trainees.
19:10Fun fact, his very first PhD student
19:13was Abraham Maslow who developed
19:16Maslow's hierarchy of needs.
19:18His dissertation,
19:19the role of dominance in
19:21social behavior of primates.
19:23But of course Harlow had other
19:25proteges who carried on his legacy,
19:27and this legacy is continued not in his
19:29original severe deprivation studies,
19:31because no one wants to do those anymore,
19:33and no one has done them for many,
19:35many years.
19:36But he trained his students in the
19:38rigorous and carefully research
19:40techniques to isolate how early life
19:43experiences shape lifelong health,
19:45and some of these trainees include
19:47his postdoc and undergrad Jim Sackett
19:49and Jerry Ruppenthal who moved
19:51together in 1970 from Wisconsin to
19:53launch the infant Primate Research
19:55Lab at the University of Washington,
19:57which still to this day, is the nation.
20:00Only 24 hours staffed infant primate lab.
20:03He also trained Melinda Novak,
20:05who after graduating a retaining her
20:07PhD moved to UMass Amherst where she
20:10recently just retired last year.
20:13But for the duration of her career
20:15ran a small primate lab,
20:18looking at primate cognition
20:20and psychological well being.
20:22And he trained Steve Suming,
20:24who Appan leaving Wisconsin started
20:26the lab of comparative mythology.
20:28Mythology at NIH,
20:29which was an operation for about 35 years,
20:32and these people are very important
20:34because they are the ones who raised me,
20:37at least academically and
20:40professionally speaking.
20:41Andres is right.
20:42I just happened to be sitting in an
20:45animal behavior class when I was an
20:47undergrad in zoology at University,
20:49Washington,
20:50and the professor mentioned
20:51infant primate lab.
20:52So to conducted my undergrad research there,
20:54I obtained my Masters and PhD in
20:57behavioral neuroscience under the
20:58guidance of Melinda Novak, and I did it.
21:01My second postdoctoral fellowship in
21:03Steve Sumes lab and my work broadens
21:05the concept of early attachments
21:07to focus on multiple early life
21:09experiences that shaped lifelong
21:11and intergenerational health.
21:14So my research goals are to identify
21:17causal mechanisms linking variable early,
21:19early life experiences to health
21:21outcomes later in life and
21:23adolescence and all hood and beyond,
21:26and these health outcomes, importantly,
21:28are both behavioral and physical,
21:30and when I say early life experiences,
21:33I really mean a wide ranging of
21:36swath of early life experiences,
21:39from prenatal and post Natal stress to
21:41various variations in maternal experience.
21:44Two naturally occurring variations
21:45and mother's milk composition,
21:46as well as the influence
21:48of early attachments.
21:49And though I would really love to talk
21:52about findings on all of these today,
21:54I'll just be focusing on the
21:57influence of early attachments.
21:58So this body of work I've been
22:01fortunate to conduct because of
22:03my time spent in Steve Sumes lab,
22:06which was an operation from 1983 until
22:08just a couple of years ago when he
22:11retired and this was an intramural
22:14research lab at the NCH Dee Ann.
22:16Its three major goals were to study
22:18the genetic and environmental factors
22:20that shape individual developmental
22:22trajectories and also to examine
22:25both the continuity and the change,
22:27that is to say,
22:28those stability of individual differences.
22:31Cross development and finally of
22:33course to identify the degree of
22:36generalizability to both wild monkeys
22:38and for our purposes here to humans.
22:41And we were able to achieve this
22:43because we could tightly control
22:45the early life experiences that
22:47monkeys were exposed to,
22:48and I'm going to take a few moments
22:51to describe those in details so they
22:53have a firm understanding because
22:55they matter for the rest of the talk.
22:57So for in our lab the rhesus monkeys
22:59were randomly assigned to experience
23:01one of three rearing conditions.
23:03For the first eight to 10 months of life.
23:06Now on average we would have approximately
23:0940 infants per year born into the colony.
23:11Anne,
23:12randomly 50% of these would be mother,
23:14period.
23:14This was our control condition Reardon.
23:16Social groups with many other adult females,
23:18adult males and other infants.
23:20The other 50% would be randomly assigned
23:22to experience a nursery ring for the
23:24first eight to 10 months of life and
23:27so from birth they would either be
23:29one of two nursery reared formats.
23:31The first is peer rearing and
23:32the 2nd is surrogate peering.
23:34So after the first month of life
23:36where infants could Thermo regulate
23:38and self feed in the nursery,
23:40they were then either randomly
23:41assigned to be period where they were.
23:44A house with other peers from
23:46three other peers 24 hours a day.
23:48Or they were housed in a single
23:50cage with a cloth covered surrogate
23:52for the majority of the day.
23:54But given daily play sessions with
23:56other surrogate period animals so they
23:58do not have continual exposure to peers.
24:01Now the research over the decades has has.
24:07Has shown us that period
24:08monkeys actually go on to become
24:10exceptionally dependent on each other,
24:12hyper dependent and the reason for
24:14that is because they both act as the
24:16secure attachment base for each other
24:18and they have a need for attachment
24:21so they're unable to break physically
24:22to break apart from each other.
24:24Starting at very young ages because
24:26of the need of others to cling on to
24:29them and so they just kind of form
24:31these huddling clusters of monkeys
24:33in response to stressful situations.
24:35Surrogate period monkeys actually turn out.
24:37Developmentally to be much closer
24:39to Mother period monkeys,
24:41but they are still different and so
24:44these protocols are substantially
24:45improved over harlows methods because
24:48in addition to providing early social
24:51experience to the nursery monkeys,
24:54which parlors did not?
24:55These monkeys were involved in numerous
24:57experiences that both tested their
25:00cognitive development emotional development,
25:02so they had everyday multiple
25:05variable rich experiences,
25:06not only with researchers.
25:09But stimulating?
25:11Sort of test sessions that would
25:14stimulate their simulate their
25:16brains and also had continually
25:19rotating environmental enrichment.
25:21Now,
25:22after the first eight to 10 months of life,
25:25these monkeys would then be reared
25:26identically in the same housing situation,
25:29therefore mimic well.
25:30We would form them into a
25:31mixed social rearing group.
25:33Now this was a really stressful
25:35event actually,
25:36because what would happen
25:37is literally one day.
25:39All the monkeys,
25:40mother period and nurtured
25:41would be up and relocated,
25:42put into a new room and said OK,
25:45Now you have to get along an imagine
25:47that you're suddenly one day taken to
25:49a new home with new people and you
25:51just have to learn how to get along.
25:55So although this was a majorly
25:57stressful experience,
25:57it was not permanently stressful.
25:59They did adapt as you'll see later,
26:01but it's important to note that they
26:03live in this mixture ING environment
26:05with identical care in treatment,
26:07essentially for the rest of their lives.
26:09Now,
26:09at three years of age,
26:11and we separated them by *** to avoid
26:14unintended pregnancies and females
26:15went back into the breeding colony,
26:17but they still maintain their
26:19mixed rearing groups,
26:19and so any differences that we
26:22observed after the first eight to 10
26:24months of life can be attributed.
26:26To the differential early
26:27rearing experiences in the first
26:29eight to 10 months of life.
26:34Now over the last several years,
26:36we've been able to look at how
26:38these different, tightly controlled,
26:39early life experiences
26:40influence multiple outcomes.
26:41In one of our primary outcomes of
26:43interest is cognitive development,
26:45which we assess in monkeys from
26:47about four to eight months of age,
26:49which is equivalent to approximately
26:51one to three years in humans,
26:53and there's a direct through line
26:55from Harlow's very early work on
26:57cognitive capabilities to our research.
26:58If you remember when I mentioned
27:00earlier the W GTA,
27:02there was constant general testing apparatus.
27:04We use that in the early work and
27:06along with standardized battery of
27:08cognitive assessments that were developed
27:10at the primate lab at Washington,
27:12where I was an undergrad in
27:14which I was trained on.
27:16But up until very recently it was
27:18only possible to administer these
27:20cognitive assessments to nursery
27:21monkeys because of the compounds that
27:23would come along with separating
27:25temporarily an infant from its mother
27:27to give a cognitive tasks well.
27:29A few years ago,
27:31we decided to tackle this and we
27:33devised a method a really simple
27:35apparatus to be able to test socially.
27:37House Mother period infants.
27:39Here on the left,
27:40in their home environments and to
27:42compare them directly with nursery
27:43reared in infants in their home environments.
27:46So we had no need for separating
27:48infants from their mothers.
27:49We got no distress responses and
27:51we weren't moving them to a novel
27:53room to do the testing.
27:55As you saw in this last picture.
27:57And I'm going to show a video of
27:59what this simple yet I I feel
28:01elegant apparatus looked like.
28:02So it was a cage within the
28:04large floor to ceiling cage,
28:06and this cage had a tiny little
28:07tunnel that only the infant was small
28:09enough to fit through so mom could not
28:11prohibit her infant from going in.
28:13And I'm here to tell you.
28:14As you can see from the video,
28:16once the babies learned that they
28:18could go in and access streets
28:19that mom couldn't get,
28:20they were they were all about it.
28:22And so you can see this one waiting
28:24and as soon as the occluder concern
28:26comes in and grabs that treat.
28:32So here are some of the tasks
28:34that we gave her infants.
28:36We gave them a simple training tasks
28:38such as simple training tasks that
28:39simply where they learn to push aside
28:42an object to retrieve a food reward.
28:44We followed that with
28:45the discrimination task,
28:46which was a measure of their ability
28:48to associate an object with reward,
28:50and so the object that was rewarded
28:52would either be a black block or a white
28:54block randomly assigned to each infant,
28:56and the presentation of
28:57those blocks would be.
28:59Randomly switched side to
29:00side across 25 trials per day.
29:03Once they pass that test,
29:04we gave them a reversal task to
29:06measure their cognitive flexibility.
29:08So if Black was previously rewarded,
29:09we then rewarded the white block
29:11and look to see how long it took
29:13them to learn this new Association,
29:15and then finally they don't have time
29:17to go into the details that video you
29:20saw in the last slide was really a
29:23task to measure infants impulsivity.
29:25And so, in our study of Mother P.
29:28Reardon nursery monkeys,
29:29we found no global cognitive
29:31differences when we looked at
29:32cognition in the first year of life,
29:34and in fact on 19 different measures,
29:37we actually found significant
29:38ring effects only for two of them,
29:40and one of them actually was on
29:42this training task,
29:43which does not really.
29:47Impact the cognitive development
29:48or what we know about cognitive
29:50development as a whole.
29:52And so this is just one example of
29:54data showing the performance on the
29:57discrimination and reversal test.
29:59Those black white tan.
30:00Now in this figure,
30:02Mother Pier and monkeys are always
30:04presented on the left of the blue line.
30:06Here nursery rhyme monkeys,
30:08which is both period answer again
30:10because they did not differ.
30:11They're always presented on the
30:13right side of the blue line and what
30:15you're looking at is that there are
30:17no rearing differences in monkeys bulk rate.
30:20That's their refusal to work and
30:22how many days it took them to pass
30:25the test and how long they took per
30:27trial to conduct the tasks or in
30:29the percentage of trials correct.
30:32And we checked this lack of differences
30:34up to the fact that all infants
30:36were very carefully acclimatized to
30:38testing procedures and to the researchers,
30:41and especially that they were
30:43comfortable in their home environments.
30:44And importantly,
30:45we didn't test cognitive capacities
30:47under mildly stressful situations,
30:48but obviously we might expect that we
30:50would see rearing differences there,
30:52and we also have not yet been able
30:55to look for differences in learning
30:57day by day or trial by trial.
31:00This is just a gross overview
31:02of cognitive development.
31:03But looking in that finer detail
31:05is something I hope to do when
31:08I have a little more time.
31:09So with techniques that have
31:11emerged in recent years,
31:13we've also been able to start probing
31:15how early life experiences get under
31:17the skin to affect later health,
31:19and one of the ways we've
31:21looked under the skin
31:22is by developing an assay to
31:24measure chronic stress by measuring
31:26the hormone cortisol in her.
31:28Now, cortisol travels through the
31:30bloodstream and is deposited into
31:32the hair shaft and accumulates
31:34over time so that when you take a
31:36sample here at the base of the skin,
31:38the base close to the skin.
31:40Surface, I mean the amount of
31:43cortisol that you get is an
31:46aggregate representation of.
31:48Hypothalamic pituitary adrenal
31:50axis activity is basically a
31:53phenotypic view of cortisol activity.
31:56And to measure cortisol we simply
31:58shave patches of hair from the backs
32:00of monkeys neck at routine intervals.
32:02And since this procedure was
32:04developed in monkeys,
32:05it's since been adapted for use in humans.
32:08Where no, we don't shave large patches,
32:10but we get very small samples with
32:13scissors and process the samples
32:15for cortisol concentrations.
32:17Now, if you were in our study
32:19of differently reared monkeys,
32:21we looked at her cortisol
32:23concentrations across development
32:24from birth through two years of age.
32:26Now remember any differences we
32:28see after 8 to 10 months should be
32:30attributable to the first months of
32:33different early life experiences,
32:34and this figure is showing you
32:37her cortisol concentrations for
32:38all three rearing groups.
32:40The blue line indicates that stressful
32:42relocation that I mentioned and 1st
32:44I want to draw your attention to the
32:46fact that prior to relocation those
32:48peer weird monkeys, the black squares.
32:50The ones I said to develop hyper attachments.
32:53Those monkeys had higher her
32:55cortisol concentrations than either
32:56of the other two groups of monkeys,
32:58just at baseline.
32:59And these her cortisol concentrations
33:02remained elevated for up to a
33:04year after the relocation.
33:06Surrogate monkeys showed a massive
33:08increase in her cortisol after relocation,
33:10which also stayed elevated.
33:12But importantly by two years of age after
33:15they had had sufficient time to acclimate,
33:18the monkeys were indistinguishable
33:20from one another.
33:22Now when we looked at these
33:25same monkeys anxious behavior,
33:26we found somewhat similar patterns.
33:28The monkeys did not develop any
33:30anxious or show very much anxious
33:32behavior in their home environments.
33:35Preload relocation,
33:35but understandably all monkeys
33:37found this to be a stressful event.
33:40An showed massive increases in anxiety,
33:42especially if they were nursery reared,
33:44but particularly for period monkeys.
33:46Again,
33:47the squares here those levels of
33:49anxious behavior remained elevated
33:51for up to one year after relocation.
33:54However, by two years of age,
33:56again,
33:56they were indistinguishable from one another.
33:58Now we wanted to know does does
34:00her cortisol in infancy before the
34:02relocation predict anxious behavior
34:04after their stressful relocation?
34:06And the answer is yes,
34:08we found a significant correlation
34:10for all monkeys.
34:11But when we broke it down by rearing group.
34:15That correlation maybe no surprise,
34:16was significant only for purity animals,
34:19an this correlation persistent again,
34:20for up to one year post relocation.
34:26Another important outcome of interest
34:27for us is socialrank attainment,
34:29which in this study I'm about to
34:31present we measured or reassessed in
34:33adolescent monkeys age 2 to three years,
34:35which is equivalent to about 8
34:37to 12 years in human children.
34:40Now, rhesus monkeys have a very rigid
34:42varying linear dominance hierarchy,
34:44which is enforced by often subtle but
34:46sometimes not so subtle behaviors.
34:48So sometimes even a sideways glance will be
34:51enough to tell one monkey who's in charge,
34:53by the way, notice in the background who's
34:56watching this interaction and learning
34:59some really important social cues.
35:01Other behaviors that reinforce the
35:03dominance hierarchy are threat displays,
35:05and then if they get a really escalated
35:07monkeys will physically chase and
35:09attack each other.
35:11Now, the way the hierarchy goes is that
35:14monkey A will always win against Monkey B,
35:17who never loses to anyone except a monkey a.
35:21But monkey be never loses to
35:23monkey see and so on and so on.
35:26And once hierarchies are formed very,
35:28they're rather stable.
35:29And so,
35:30although there are important differences,
35:32rhesus monkey social status is a good
35:34proxy of socioeconomic status in humans,
35:36because those at the top have greater
35:39access to resources like social partners,
35:41desirable social partners,
35:42better food,
35:43or first access to food.
35:44The best shelter which for monkeys
35:47is a shady spot on a hot day,
35:49and both monkeys and humans use their
35:52power to access those resources.
35:54So in our study of juvenile monkeys,
35:57we found that nursery reared
35:59juveniles both period and surrogate
36:01reared occupied lower social
36:02ranks than mother reared monkeys.
36:04And this was a finding that held
36:07true for adults as well once they
36:09were eight to eight years or older.
36:12But we had an interesting caveat here.
36:15So we looked to see whether her cortisol,
36:18the chronic stress measure,
36:19could was affiliated with social rank and
36:22in adulthood only for Mother Period monkeys,
36:24which is the solid black line.
36:26Was there significant correlation such
36:28that mother period monkeys with higher
36:30her cortisol indicative of greater stress,
36:32ranked lower on the hierarchy?
36:34But this a filler.
36:36This relationship was not present
36:38for the nursery room monkeys,
36:40so we look back in time to that stressful
36:44relocation and we found that once
36:46again from other peer reared monkeys,
36:49only their ability to regulate cortisol,
36:51their changes in cortisol across
36:53several months following relocation
36:55significantly predicted their dominant
36:57status only if they were mother appeared,
36:59and so this suggests that there
37:02is a stress regulation is.
37:04Is out of wack in nursery monkeys
37:07an that this dysregulation likely
37:08begins in adolescence and maybe a
37:11predictor of adult social status.
37:16So recall that I just showed
37:18you that higher ranking monkeys
37:19are more likely to be mother,
37:22period, and this is a particular
37:24importance for this next study,
37:25which examined differential DNA metalation
37:27in the placenta of high middle ranking
37:30monkeys versus low ranking monkeys.
37:32And remember the high ranking
37:34monkey placentas are more likely to
37:36come from mother period animals.
37:38And so we studied DNA methylation
37:40as another way to look under this
37:43skin because DNA changes the
37:45activity of a DNA sequence without
37:47changing its structure or sequence.
37:50An importantly,
37:51because Miss Metalation typically
37:52acts to alter later gene expression.
37:56And so we found dramatic differences
37:57in DNA methylation in the placenta
37:59of monkeys that were high ranking
38:01versus low ranking,
38:02and that's what this heat map
38:04here is showing you.
38:05All you need to know is the high,
38:07medium, low rank,
38:08high medium ranking monkeys are on
38:10the left side and the low ranking
38:12monkeys are on the right side.
38:14An blue is low levels of metalation
38:16red is high levels of metalation.
38:18You could see that their patterns
38:20of methylations are essentially
38:22opposite each other.
38:23And further,
38:24exploration revealed that the dramatic
38:27differences in Diamet DNA metalation
38:29were particularly located in networks
38:32that are critical to cell morphology,
38:35cell growth and differentiation,
38:37and cell signaling.
38:39All vital,
38:40important, vital,
38:41and functions for placental Physiology.
38:43We also found that the upstream
38:46regulators of these gene networks included
38:49glucocorticoid receptor target genes,
38:51which indicates to us that.
38:54The stress stress response is
38:56particularly important here,
38:57and so the broad scope of
39:00methylation differences here,
39:01as well as the fact that these
39:04metalation differences affected tissue.
39:05That's vital for fetal development,
39:07really illustrates the profound biological
39:09effect that socialrank likely achieved,
39:11partly by early rearing may
39:13have on the next generation,
39:15and this is important because
39:17in translating it to humans,
39:19these have really important implications
39:22for our understanding of the impacts
39:24of social equality or inequality.
39:26Of the well being and care of pregnant women,
39:30and it underscores the need for
39:32appropriate interventions for women,
39:34particularly those who may be
39:36disadvantaged and more likely
39:38to suffer from social stress.
39:40And so this body of work represented
39:42one of our first forays into
39:45the intergenerational effects.
39:46Of early secure attachments.
39:48Because the placenta is of fetal
39:50origin and so therefore we may be
39:53starting to see here in this study
39:55the impacts of secure attachments
39:57on the next generation.
40:02So only now has it been possible to
40:05extend the findings of Goon Park.
40:07Beyond offspring development an
40:09into multiple generations and
40:10we can do this now because we
40:13have transferred the entire NCH,
40:15the rhesus monkey data set.
40:16Both biological and behavioral
40:18to the Yale Child Study Center.
40:20So we now hold longitudinal perspective
40:23and comprehensive data collected over
40:25the course of 25 years or more on
40:27multiple generations of monkeys in
40:29sufficient numbers to be able to begin.
40:32To rigorously test the causal
40:34influences of disruptions to
40:36early secure attachments and some
40:38of the data we hold include.
40:40Thousands like 25,000 or more
40:43biological samples, blood plasma,
40:45Cerebro, spinal fluid saliva,
40:47extracted DNA RNA,
40:49white blood samples and hair samples,
40:52among others.
40:53We hold extensive neonatal assessments,
40:56measuring neurological development
40:58and function across the first month
41:01of life on multiple generations.
41:04And we have health records,
41:06weight and BMI data,
41:08pregnancy outcomes, social behavior,
41:09rank data and much more.
41:14And one of the aspects that makes this
41:17archival data set such a goldmine and so
41:19unique is that we have data on multiple
41:22generations of monkeys that were reared
41:24in one of four different sequences.
41:27So we help now hold intergenerational
41:29data on mother offspring pairs that were
41:32either mother, period, mother period.
41:34So the mothers themselves were
41:37weird with their mothers and their
41:39infants were mother reared.
41:41Or we have a data on monkeys who
41:44were reared by their mothers,
41:45but their infants reared in the nursery.
41:49We have data on monkeys who were who
41:50were the mothers were nursery reared,
41:52and their infants were also nursery.
41:54Weird and where mothers were nurtured.
41:56But they reared their own infants.
41:59And so, several years ago we forged a
42:02unique collaboration with behavioral
42:04economists at the University of Chicago,
42:06led by Doctor James Heckman, who,
42:09as Andres mentioned at the outset,
42:11was the Nobel Laureate in Economics in 2000,
42:15and is best known for his birth to
42:18five research and policy advocacy now.
42:20This collaboration,
42:21previously found single generation effects
42:23of different early life experiences,
42:25so the work found that that
42:28monkeys experiencing adverse.
42:29Adversity early in life via lack of a
42:32secure attachment had adverse health
42:34outcomes in adolescence and adulthood.
42:37But we're now extending this work with
42:40the collaborators of pictured here,
42:42to study the causal effects of different
42:44early attachments on subsequent generations,
42:46and this is the work I'm going
42:49to finish out with today.
42:51So with funding from the National
42:52Science Foundation in this
42:54first intergenerational study,
42:55we capitalized on the randomization of
42:58early life experiences in monkeys to
43:00quantify the degree of the impact that
43:02maternal presence has on offspring health.
43:05And we published these findings recently.
43:07In a working paper at the National
43:10Bureau of Economic Research,
43:11and we address a major limitation in
43:13human studies by being able to carefully
43:16control the early life experiences of
43:18monkeys and study them across generations.
43:20And so these four rearing sequences
43:23that I just showed you allow us
43:25to test on the one hand,
43:27the potential benefit of sustained,
43:29secure attachment across generations
43:30here in the Blue Square and on
43:33the other hand we can also test
43:35whether it's possible to compensate.
43:37For a lack of secure attachment.
43:40Here in the red, on the right,
43:43and by comparing the differences in
43:46outcomes between the intergenerational
43:48groups here in the orange,
43:49we can describe how the effects
43:52on the offspring depend on the
43:54parents early rearing environments.
43:56An this comparison is something that
43:59economists call intergenerational
44:00complementarity,
44:00and this analysis allows us to
44:03learn more than just the benefit
44:05of secure attachments in a single
44:07generation the mother's generation.
44:10We can now learn about the
44:12importance of sustained,
44:14secure attachments across generations,
44:15as well as the importance of investing
44:19early in the parents generation versus
44:21trying to compare or to compensate
44:24in the offspring's generation.
44:26So our behavioral economics economist
44:28friends use their sophisticated equation
44:30modeling to conduct all these tests,
44:33which I call fancy voodoo magic
44:35and to calculate these benefits.
44:38So we relied on archival data from
44:41over 650 mother offspring pairs
44:43with roughly equal representation
44:45across the four rearing sequences.
44:48An we first focused on initial
44:50intergenerational impacts,
44:51namely pregnancy outcomes did the infant's
44:53birth result in a live birth yes or no?
44:56Did the infant survive past the first
44:59month and what was its birth weight?
45:01And these can be considered pre
45:03treatment outcomes since most of them
45:05occur prior to randomize conditions.
45:09Now we found no intergenerational
45:11effect on the probability of an
45:14offspring being born live versus
45:16stillborn or on its birth weight.
45:18But we did find significant intergenerational
45:20effect on infant survivability,
45:22so infants of moms who were reared with
45:25their mothers had a survival rate that
45:28was 2.9% higher than infants reared
45:30by mothers who were nursery rears.
45:32I'll say that one more time the infants and
45:36mothers whose own mothers were mother weird.
45:40Had a 2.9% higher survival rate than
45:43infants whose mothers were nursery reared.
45:47So we then examine long term
45:50intergenerational impacts,
45:50both of which occurred after the
45:53experimental rearing conditions ended.
45:55After that relocation,
45:56and unlike the previous results,
45:58these outcomes can be affected both
46:00by the mother's ring condition and
46:02the offspring zone rearing condition.
46:05One of these outcomes was adolescent health,
46:08measured at one to three years,
46:10which is approximately 4 to 4
46:13to 12 years in humans.
46:15And for this we looked at the
46:18percentage of quarterly vet exams in
46:20which the animal was in good health,
46:23meaning the animal did not require treatment
46:25for a problem like wounding diarrhea,
46:28which is common in monkey colonies,
46:30skin rash,
46:31dermatitis surgeries, etc.
46:32And in adulthood we measured
46:34their social rank attainment
46:35and this was actually earlier.
46:37The age span range from 2 to 15 years,
46:40but the majority of animals were
46:43in adulthood.
46:45An the hear their relative rank in
46:48their social groups range from 0.05
46:50lowest on the totem pole to 1.0 highest.
46:54Alright,
46:54so for both health and social status,
46:57the only significant effects again
46:59war for Mother period offspring
47:01whose mothers were themselves
47:02mother reared for good health.
47:04This resulted in an increase of 6.7
47:07percentage points and for social rank.
47:10This resulted in an increase of .17 points,
47:13which is pretty remarkable
47:14considering the scope of the scale.
47:17Here I should say there were
47:19no no significant effects for
47:22other rearing sequences.
47:24So the big question is,
47:26is the difference in
47:27intergenerational effects Mother
47:28period versus nursery offspring?
47:30Is that statistically significant?
47:32Well,
47:32we formally tested this again
47:35by measuring intergenerational
47:37complimentarity and the answer is yes.
47:39We found a strong and significant
47:42intergenerational complementarity such
47:44that the effect of secure attachment
47:47is more beneficial for offspring whose
47:50mothers also had a secure attachment.
47:52And the effect was as follows.
47:55Mother periods,
47:56offspring time and good health was
47:58increased by 9.7% versus nurture
48:00offspring and socialrank was
48:02increased by .24 points more and
48:05then for nursery reared offspring.
48:07Now because only mother period offspring
48:09can interact with their mothers.
48:11But nursery monkeys cannot.
48:13Any positive effects on Mother Period.
48:16Offspring here must be post needle
48:18because the in uteral prenatal
48:21effects were the same for both groups.
48:24So we therefore conclude that
48:26the improved parenting received
48:27by Mother Period offspring,
48:29because their own mothers had
48:31secure attachments early in life.
48:33This improved parenting is the
48:35primary channel through which
48:36early life advantage in the
48:38parents generation in the form of
48:40a secure attachment is transmitted to
48:43the next generation versus prenatal in
48:45utero effects an it's clear now that
48:48these affect start very early in life,
48:50as evidenced by survival rates
48:52and persist until adulthood,
48:54as evidenced by socialrank.
48:58So these first findings on intergenerational
49:01effects of early advantage have
49:04really important implications.
49:05There is strong importance to ensure that
49:09all children experience secure attachments,
49:11particularly children who start
49:14out life in with disadvantage.
49:17These findings also really underscore
49:19the need for investments into parents
49:22and families not just into children or
49:25infants so that families can engage
49:27in forming secure attachments with
49:29their children and when parents and
49:32caregivers and families are denied,
49:34denied. Access to.
49:37Abilities to enable them to
49:40meet their basic needs,
49:42they just don't have the
49:44resources to Additionally be able
49:46to form the secure bonds.
49:47So when they're denied
49:49extended paid parental leave,
49:50both mothers and fathers when they
49:52don't have access to high quality early
49:55childhood education an also by the way,
49:58when early educators are
50:00not paid appropriately.
50:01When people don't have a living
50:03wage and when they lack food,
50:05housing and health security,
50:06you can begin to see how it could be
50:09much harder to invest the resources
50:11needed in forming secure attachments that
50:14those of us with more privileged means have.
50:18So what's next?
50:19Well,
50:20with current and future funding,
50:21we aim to identify the biological
50:24mechanisms of secure attachments.
50:25At least some of them,
50:27and so with this current NSF funding
50:30in collaboration with Michael Kobor
50:31at University of British Columbia,
50:34we're going to look at DNA
50:36metalation across generations.
50:37As one of these under the skin
50:39mechanisms an we're also going to begin
50:42probing in inflammation both within a
50:44single generation an across generations,
50:46and I've just recently been awarded.
50:49This pilot award from the animal
50:51models for the social dimensions of
50:53health and Aging Research Network,
50:55which is a National Institute
50:57of Aging Research Network,
50:58to start looking at a chronic
51:00inflammation across the life course,
51:02and I plan in the next few months to
51:05apply for further funding from the
51:07foundations and institutes you see here,
51:10including one opportunity.
51:11I'm really excited about.
51:12Again from NIH.
51:13It's for early stage investigators
51:15using nonhuman primate models.
51:17And in addition to these two DNA,
51:20metalation information will
51:22obviously also be probing for
51:24other biological mechanisms.
51:26I also want to take a moment to talk
51:29about how we're expanding our hair.
51:32Cortisol or chronic stress studies
51:34so we're acquiring equipment now to
51:37set up a lab to be able to run her
51:39cortisol assays here in house at Yale,
51:41and I'm really bummed because
51:43right before Pandemic hit and we
51:45were required to go into lockdown,
51:47I was just preparing an IRB protocol
51:49to study with a colleague and
51:52collaborator University of Virginia.
51:53A different type of early life
51:55experience and that is bearable.
51:57Educational environments,
51:58so we're going to compare a children
52:01in public Montessori schools
52:04with standard public education.
52:06Pedagogy and look at see how their
52:08hair cortisol change across the
52:10year and how that influenced their
52:12academic and social emotional outcomes.
52:14So we hope to resume this once
52:16it's safe to do so with additional
52:18colleagues at University of Chicago,
52:20we just submitted a research grant,
52:22a small pilot award to look at
52:25the hair cortisol of black mothers
52:27whose prenatal and post Natal care
52:29has been disrupted due to covid.
52:32And with colleagues here at
52:34the Yale School of Nursing,
52:35we're about to submit a grant
52:38to the National Heart, Lung,
52:40and Blood Institute to examine
52:42how chronic stress may be,
52:44what role it may have in a sleep
52:46disorders and cardiovascular function.
52:48But one could also envision
52:50studying other hormones in her.
52:52It's possible to measure,
52:54for example, progesterone,
52:55estradiol and testosterone,
52:56and maybe some of you have an interest
53:00in studying other elements in her.
53:02That might measure environmental
53:03exposures like trace elements or
53:05heavy metals or tobacco exposure.
53:07So if any of these sound interesting to you,
53:10please get in touch with me after the talk.
53:15And so with that I would like to
53:17conclude by acknowledging our funders
53:19have made all of this work possible
53:21today that I've shared with you,
53:23along with the numerous people who work
53:25behind the scenes to present these data.
53:28And I would be remiss if I did not
53:30acknowledge my own caregivers who gave
53:32me the best form of secure attachment
53:34from the moment I was born two months
53:37early as a preemie who could fit in
53:39a shoe box all the way up until now.
53:42Not only do they provide me with
53:44the secure loving base, but.
53:46Pretty good peer interactions
53:47with my sister too.
53:49So with that I'm going to leave you
53:51with one more quote by Harry Harlow,
53:54perhaps, and in which he was describing.
53:57An anecdotal behavior he had seen where
54:00a monkey used a stick as a weapon.
54:03Perhaps we should be criticized for
54:05not reporting these behaviors earlier,
54:06but in my defense,
54:08let me state that in the mid 30s,
54:10comparative psychology had attained
54:11a level of objectivity that made
54:13reporting such behavior a matter
54:15of grave risk to the reputation
54:16of any ambitious young scientists.
54:18And it is better to become famous
54:21slowly than to be right all at once.
54:24Alright, so that is it.
54:26Thank you very much all for being
54:29here and and especially for you know,
54:32enlightening me in here and let me
54:34regale you with my monkey tails.
54:37So thank you. Amanda, thank you so much.
54:42We are out of time,
54:43but we're going to leave them open and
54:45I'll stick around and whomever wants
54:47to stick around Papparazi's questions
54:48if you need to leave, that's fine.
54:50If you want to stay hang out but Amanda,
54:53thank you. I will be so much.
54:55Yes,
54:55thank you so much for the invitation on
54:57race and I really hope to see as many of
54:59you as possible in person again soon.
55:02Thank you.