Chapter 7 & 8
Primate Behavior & Models for
Human Evolution
The Evolution of Behavior

Behavior

An action in response to internal or external stimuli.
Response to environment.

Deliberate or unconscious.


Behavioral Ecology
Natural environment
Behaviors
Biological traits
Genes
The Evolution of Behavior



Behavioral phenotypes transmitted
genetically at faster rate than others.
Genetic + Environmental Factors =
Behavior
There are different limits & potentials for
learning in various species.

(i.e. Rabbit vs. Chimpanzee)
Primate Social Structure


Social structures result
from natural selection.
Primates are among the
most social of animals.

Factors Influencing Social
Structure:










Body Size
BMR & diet
Distribution of Resources
Predation
Relation to other species
Dispersal
Life histories
Sleeping sites
Activity patterns
Human activities
Primate Social Behavior:

Dominance
 dominance hierarchies.
 Access to resources.
 Factors influencing dominance status:




Sex
• Intelligence
Age
• Motivation
Aggression
• Mother’s social position
Time in the group
Primate Social Behavior:
Communication

Autonomic vs. Deliberate communication.



Reassurance is communicated through hugging or
holding hands.
The fear grin, seen in all primates, indicates fear and
submission.
Displays

communicate emotional states.
Primate Social Behavior:
Aggression & Affiliative Behaviors





Competition for resources
Signals & displays
Tense situations
Core area & territorialism
Affiliative behaviors
 Physical contact
 Altruism
Patterns of Reproduction



Estrus Cycle
No permanent bonding
Reproductive strategies
 K-selected & R-selected
 Male competition for mates
= sexual selection
Sexual Selection




A type of natural selection that operates
on one sex, usually males.
Increase frequency of traits (successful
mates).
Sexual selection dimorphism
Infanticide as a reproductive strategy?
 Reasons
Primate Cultural Behavior




Basic social unit
Polygamous relations, males
are not active.
Experiments with orphan
Monkeys.
Do apes have culture?

Learned through observation

Examples of culture
Language



Communicating abstract thoughts.
Closed system of communication
Challenges to these views:
 Vervet monkeys
 Distinct calls for specific references
 Film examples
The Primate Continuum



Humans have bigger brains but same
neurological processes.
Ethical dilemmas in the study of our closest
relatives.
 Should we study/exploit them for our benefit?
 We cage nonhuman primates without regard
for their needs.
Nonhuman primates should be maintained in
social groups and introduced to habitat
enrichment programs.
Quick Quiz
1. Dominance hierarchies
a) guarantee that dominant males are
more reproductively successful.
b) result in dominant individuals having
priority access to food.
c) don't guarantee a reproductive
advantage in dominant males.
d) are permanent.
Answer: b

Dominance hierarchies result in
dominant individuals having priority
access to food.
2. Affiliative behaviors
a) arise when there is competition for
resources.
b) enhance group cohesiveness.
c) are rare among primates.
d) may include displays.
Answer: b
• Affiliative behaviors enhance group
cohesiveness.
3. Vervet monkey communication
a) is used to support the theory that
primate vocalizations do not include
external events or objects.
b) is limited to scent marking and an
occasional bark.
c) includes specific sounds for different
categories of predators (air, tree or
ground).
d) is sophisticated with regard to food.
Answer: c

Vervet monkey communication includes
specific sounds for different
categories of predators (air, tree or
ground).
4. In a group's territory there is usually a
_________________ area where the
highest concentration of resources can be
found.
Answer: core

In a group's territory there is usually a
core area where the highest
concentration of resources can be found.
In Class Primate Activity
Using information from chapters 6 & 7 in the
text and the films, form small groups to
discuss the following questions:
1.
2.
3.
What are some similarities humans share with primates?
(anatomical & behavioral) List 5+
Define and give an example (3)of the following primate
behaviors:
1.
Altruism, aggression, communication, dominance &
reproductive strategies.
List the following:
1.
Three examples of Prosimians and Anthropoids as well as
their characteristics
2.
Discuss why infanticide is seen as reproductive strategy. Do
you agree? Why or why not?
3.
Describe and give examples of language & cognitive abilities
of apes. Do apes have language or only humans do?