AN263
Behavioral Biology
Midterm Exam
2024
Misconceptions About the Interaction Between Behavior and Biology
1. 1-on-1 relationship between genes and behavior
a. EXAMPLE: there is one gene that controls for aggression
2. If something is “natural” or biological, it is right or justified (naturalistic fallacy)
a. EXAMPLE: male aggression against women (“boys will be boys”)
3. Behavior is either nature or nurture
4. If something has a biological basis, it can’t be changed (biophobia)
**These aren’t the approaches used to study human behavior**
Biological Anthropology Approach to Studying Human Behavior
Focus on humans as a species and what’s in common (behaviors) across cultures
Explore reasons for why human cultures may differ
MODEL 1: Biology and Behavior Behave in a Facultative Manner
Behavior and biology interact with another in response to change (facultative
manner)
Biologically based behaviors are not necessarily less alterable than
culturally constructed behaviors – even biologically based behaviors can
respond to change
EXAMPLE OF MODEL 1: Differential Investment in Offspring
Differential investment in offspring depends on the situation change the
situation, change the pattern of investment (reflecting what we would predict in
biology, but involves a cultural layer too)
o Triver’s Willard Hypothesis: Natural selection should favor biased
investment in offspring according to anticipated future reproductive
success
Mother in good condition should favor sex with greatest
variance in reproductive success (son, if males can have lots
of offspring)
Mother in poor condition should favor sex with least variance
in reproductive success (daughter, if females can have few
offspring)
o Biologically Based Motivational System: Parents evolved to respond to a
wide range of social and environmental cues relevant to productive and
reproductive contributions of offspring
Bias against daughters in China: wealth is passed down through
males and wealthy men have more than one wife (sons lead to
higher parental reproductive success)
Bias against sons in Yaaku of Mukogodo: daughters marry higher
, status males in nearby communities and sons rarely
marry/reproduce (daughters lead to higher parental reproductive
success)
MODEL 2: Tinbergen’s Explanations of Behavior
Phylogeny (Evolutionary History): Looking at the evolutionary history of “the
behavior”
through closely related species
, o Intra-sexual competition in non-human primates can help
phylogenetically explain aggressive behaviors in humans
Adaptation (Ultimate Function): Looking at the relationship between “the behavior”
and
survival/reproductive success
o Aggressive behaviors can help survival in times of war and in times
when you need to physically defend yourself
Mechanism (Proximate Function): Looking at the hormonal, neurobiological, and
psychological causes related to “the behavior”
o Fight-or-flight (hormonal/cognitive) physiological response can trigger
aggressive behaviors
Ontogeny (Development): Looking at the genetic, environmental, and accidental
contributions to “the behavior” across the lifespan
o Physical abuse experienced during childhood might contribute
to the development of aggressive behaviors later as an adult
MODEL 3: Proximate Versus Ultimate Approaches
Proximate Approach: how things happen, physiology, immediate causation
Ultimate Approach: why things happen, evolutionary explanation, adaptive
significance
MODEL 4: The Life History Approach
The relationship between culture and biology changes across the lifespan
Behavioral Biology
Midterm Exam
2024
Misconceptions About the Interaction Between Behavior and Biology
1. 1-on-1 relationship between genes and behavior
a. EXAMPLE: there is one gene that controls for aggression
2. If something is “natural” or biological, it is right or justified (naturalistic fallacy)
a. EXAMPLE: male aggression against women (“boys will be boys”)
3. Behavior is either nature or nurture
4. If something has a biological basis, it can’t be changed (biophobia)
**These aren’t the approaches used to study human behavior**
Biological Anthropology Approach to Studying Human Behavior
Focus on humans as a species and what’s in common (behaviors) across cultures
Explore reasons for why human cultures may differ
MODEL 1: Biology and Behavior Behave in a Facultative Manner
Behavior and biology interact with another in response to change (facultative
manner)
Biologically based behaviors are not necessarily less alterable than
culturally constructed behaviors – even biologically based behaviors can
respond to change
EXAMPLE OF MODEL 1: Differential Investment in Offspring
Differential investment in offspring depends on the situation change the
situation, change the pattern of investment (reflecting what we would predict in
biology, but involves a cultural layer too)
o Triver’s Willard Hypothesis: Natural selection should favor biased
investment in offspring according to anticipated future reproductive
success
Mother in good condition should favor sex with greatest
variance in reproductive success (son, if males can have lots
of offspring)
Mother in poor condition should favor sex with least variance
in reproductive success (daughter, if females can have few
offspring)
o Biologically Based Motivational System: Parents evolved to respond to a
wide range of social and environmental cues relevant to productive and
reproductive contributions of offspring
Bias against daughters in China: wealth is passed down through
males and wealthy men have more than one wife (sons lead to
higher parental reproductive success)
Bias against sons in Yaaku of Mukogodo: daughters marry higher
, status males in nearby communities and sons rarely
marry/reproduce (daughters lead to higher parental reproductive
success)
MODEL 2: Tinbergen’s Explanations of Behavior
Phylogeny (Evolutionary History): Looking at the evolutionary history of “the
behavior”
through closely related species
, o Intra-sexual competition in non-human primates can help
phylogenetically explain aggressive behaviors in humans
Adaptation (Ultimate Function): Looking at the relationship between “the behavior”
and
survival/reproductive success
o Aggressive behaviors can help survival in times of war and in times
when you need to physically defend yourself
Mechanism (Proximate Function): Looking at the hormonal, neurobiological, and
psychological causes related to “the behavior”
o Fight-or-flight (hormonal/cognitive) physiological response can trigger
aggressive behaviors
Ontogeny (Development): Looking at the genetic, environmental, and accidental
contributions to “the behavior” across the lifespan
o Physical abuse experienced during childhood might contribute
to the development of aggressive behaviors later as an adult
MODEL 3: Proximate Versus Ultimate Approaches
Proximate Approach: how things happen, physiology, immediate causation
Ultimate Approach: why things happen, evolutionary explanation, adaptive
significance
MODEL 4: The Life History Approach
The relationship between culture and biology changes across the lifespan
