The Human Primate
Primatology got started because people wanted to know more about humans.
If you want to know what makes us humans different from other animals,
it's pretty much a comparative framework you have to use. You must
compare humans to other primates and to other animals to see what sets us
apart. As we saw last time, language is something unique to humans, but
you have to look at which parts are different and which parts are the
same for other animals. We're going to look at four ways people have used
primates to understand human behavior better.
|It is important to keep in mind that sometimes when
you begin talking about human behavior using a comparative perspective,
people get upset about it and resist it. |
This is because of the naturalistic fallacy. This
fallacy says that whatever is 'natural' is in some way right or moral. If
you think about it, you can see that that is a fallacy- lots of things
like disease and famine are natural but we don't think those are right or
that they're inevitable. So for instance when you start talking about
male sexual coercion or infanticide, and you start to try and understand
it from an evolutionary perspective, some people will say that you're
trying to justify it and say that it's ok. This is not the case!
There is a difference between what exists and what is
right. It is always useful to try and understand what exists in
the world even if we don't like it or if we don't approve of it. So
remember, what is normal/natural is not necessarily what is moral, right,
Humans are flexible animals and we control our own behavior.
Nonhuman primate species as models
This is one of the earliest forms of the comparative approach- people
have chosen a particular species to try and explain how we are now or how
our ancestors might have been like. One obvious way that this has been
done, and very effectively, is in biomedical research; one primate isn't
too much different from another. We have mentioned how the Rh factor came
from rhesus monkeys, and how chimps are used in aids research, etc.
People have also used primate species as models of human behavior. This
was originally the reason for anthropology departments to study primates.
Early scientists, especially Washburn, wanted to know what primates could
tell us about early humans. There have been a few ideas about how to
choose the species you're going to get your information from- one is that
you should look at primates who live in similar conditions to our
ancestors- savannah baboons are a good example of this. Other people
thought you should look at the most closely related species- chimps or
some of the other great apes.
This has pretty much gone out of favor, however. There are several
hundred species of primates and at least that many different human
cultures-so it's too easy to find correlations and parallels. There's so
much variability that you can back up pretty much any argument.
This is not to say that using primate models of behavior hasn't been
useful. Particularly when the species and the question have both been
chosen carefully, it has been helpful. Experiments with primates have
been useful in psychology in studies on topics like motivations, drug
- Example: Social development
- This was done on rhesus monkeys to study social development in
infants. It was found in countless studies that if an infant was deprived
of social contact then it would grow up pretty screwed up- it would
develop abnormal behaviors, and if you put it in with normal monkeys it
would be overwhelmed by all the other monkeys. Then they thought, "Can
these guys be resocialized by being put in with young normally raised
babies who aren't threatening?" And it turned out that the pathological
tendencies went away and they became normal monkeys. Then people did the
same thing with kids who had been deprived at crucial parts of their
lives and made them better.
- Example: Mother-infant separation
- This was also studied in rhesus macaques and pigtail macaques. They
found that infants, when separated from their mothers, went though all
these stages of separations- protest, despair etc. The saw the same thing
with rhesus and pigtails, but in bonnet macaques, the infants don't go
through all this psychological trauma. It's pretty clear why if you look
at their social organization- there are a lot of allomothers in bonnet
macaques and babies are often left by their moms in the wild and someone
else will take care of it and bring it back to her later. So it's
important to pick more than one species and to compare across species
when you're doing this comparative approach for behavioral models.
Comparative analysis of human social organization
This method compares humans with what we know about all primates in
Up until the 60's, we didn't know anything about nonhuman primate social
organization. Levi Strauss said in 1949:
"The social life of monkeys does not lend itself to the
formulation of any norm. Whether faced by male or female, the living or
the dead, the young or the old, a relative or a stranger, the monkey's
behavior is surprisingly changeable. Not only is the behavior of a single
subset inconsistent, but there is no regular pattern to be discerned in
Of course we know this isn't true- primates recognize kin, strangers,
friends, past sexual partners, and they know who is related to whom.
A more recent analysis
It isn't necessarily true that the main difference between humans and
primates is based solely on our widespread use of symbols, but this is
what people generally point to for what determines us from other
primates. Using standard primatological approaches, however, how do
humans look when compared to other primates? Some people here at UM
looked at human society as a primate society. Of course there are a lot
of different cultures. They focused mainly on traditional cultures which
resemble what our ancestors probably lived like.
When you look across human cultures there's plenty of things that are
different but there are some features that are pretty common;
- Usually, females disperse and males stay in their natal
- Social organization is usually fission-fusion; We live in larger
communities but don't all stay together at once. We break into smaller
parties for daily life.
- We do, however, collect into stable groups to sleep together at night
in a central place, while most fission-fusion primates sleep with
whoever's there when night falls.
- Humans are mostly monogamous, but mildly polygynous.
None of this is really out of the ordinary.
These people also looked at what kind of relationships were maintained
between individuals. They decided that these were crucial relationships
in that species.
Maintain Relationships with
|non-kin only||no other male||male kin|
|non-kin only||mantled howler||mountain
red colobus, chimp,
|no other female||saddleback
tamarin||gibbon, titi monkey, orangutan|
|female kin||gelada baboon,
capuchin||black and white|
They found it interesting that humans are the only species in which both
sexes maintain social ties with kin, even after dispersal. This is
probably important because it leads to extensive alliances between
groups. In most primate species you can find stuff kind of like the human
family, but they don't really have too many ties with other groups. But
in humans, although we form families, we also make kinships ties through
the males and the females. This is in spite of the fact that we
don't have day-to-day contact with all these people. Scientists think
this is only possible because we have this symbolic communication, and
can speak of removed things.
We also are different because we (both sexes) cooperate with non-kin
However, males cooperate with each other a lot in conflicts with other
males. Females cooperate with each other a lot, but in non-conflict
situations. In other primates, females help each other in conflicts, but
in humans it's males extensively and females rarely.
This approach is purely descriptive- it's not to explain things or to
understand them, but just to know what trends there are. So it's still
left for someone else to generate hypotheses and tests and to see which
behaviors are causes and which are effects and stuff like that in terms
of human evolution.
This is another way of using primatology to study humans. This method
uses principles originally adapted for studying animal behavior and
applies it to humans. Human ethologists follow pretty traditional
ethological principles and use Tinbergen's four questions (development,
causation, evolutionary, and survival/reproduction value). Tinbergen said
these were the four kinds of questions you could ask about any animal's
behavior. Human ethologists have also adopted the same techniques that
animal behaviorists use; Usually when people studied a culture, they'd
watch it, participate in it, interview people, and ask the why they did
certain things. But in studying animals, you can't interview them. So
human ethologists use these same methods of direct behavioral
observation. This is also useful in studying infants who aren't verbal or
in studies of young children whose answers aren't particularly reliable.
People used to study the development of friendship in humans, and they
would just ask kids who their friends were, but it turns out kids aren't
good at distinguishing between who their friends are and who they wish
they were. So it's easier to just watch and make notes.
Using principles from primatology
This is the last way in which primatology is used to study humans. This
is not so much assuming humans are like any particular primate, and not
using the techniques of primatology, but using the theories of
primatology and seeing if they can be used to look at humans as well.
- Kinship theory
- This was traditionally a major focus of traditional
socioanthropologists, but has fallen out of favor recently, but has
always been popular with primatologists. People began to go back and
apply it to humans. Mark Flynn did a study on a village in Trinidad and
studied kinships. There were a number of stepfamilies where there were
both full and step-children, and he wondered whether it affected the
amount of investment from the father and found that it did indeed. Kids
received less care when they weren't related to the father.
In this study, he also found that the % of interactions between kid and
dad which involved conflict was about 3.5% for the genetic offspring, and
7% for the non
genetic offspring. This wasn't child abuse but just conflict of some
Another pair did a study on child abuse in Western society. They
hypothesized that child abuse might be related to the amount of
investment. They looked at child abuse rates in households with two
genetic parents vs households with one genetic parent and one
step-parent. Across all age groups, child abuse was much greater in
families with one step-parent. Also, it was a lot higher in younger
- Sexual selection theory
- David Busse wrote a book and looked at human mate choice within a
sexual selection framework. Remember that males are limited by access to
females while females are limited by access to resources so males tend to
be indiscriminate and females tend to be choosy. This guy looked at mate
choice in humans and found there's a fair amount of choosiness in both
species. Based on sexual selection theory, you'd expect males to be more
interested in things that reflect a woman's ability to bear children,
while women should be interested in the things which show that the male
is able and willing to invest in the kids- so men looking for mates
should pay a lot of attention to things that could indicate health,
youth, fecundity etc, while women would be expected to look at status and
wealth which indicate the male's ability to invest in offspring.
Another study has possible parallels which might have already occurred to
us, but we might be interested to see results.
The question is, do males and females behave in the way you'd expect from
sexual selection theory. Some researchers went to Florida State
University and choose nine "reasonably attractive" undergrad helpers.They
approached random members of opposite sex and said the following.
"I've been noticing you around campus and I find you very attractive.
|"...come over to my
|"...go to bed with
This certainly seems to indicate that humans behave like you'd expect
them to as primates.
So these methods don't give us complete parallels, but they can give us
information that we wouldn't come by using other methods.