evolution Flashcards
1
Q
what are the role of genes in human behaviour
A
- contains set of instructions and is a carrier of info
- inherited - 50% from each biological parent
- genotype: genetic constitution of individual
- phenotype: result of interaction between inherited characteristics and environment
- psychologists are interested in separating nature from nurture as they want to find causes for behaviour
2
Q
what is evolution
A
- how inherited characteristics in organisms evolve from generation to generation
3
Q
how are genes developed?
A
- through evolution
- through mechanism of survival of the fittest
- we all inherit genes from parents and characteristics that come from our genes are also inherited
4
Q
what is natural selection
A
- way some characteristics might aid survival over other characteristics which don’t help survival
- means that we’re the best of what we could be
- all our inherited characteristics are those that helped our ancestors to survive and reproduce
- unhelpful characteristics wouldn’t be passed on through reproduction (survival of the fittest)
5
Q
what are the two explanations for evolution?
A
- survival of the fittest
- natural selection
6
Q
aggression and natural selection
A
- aggression might be something that led to survival in certain environments such as aggression against threat in order to protect offspring
- in this way aggression can be explained using the theory of natural selection
- aggression might aid survival of the genes if a male is aggressive to protect a female mate or their child
- it is interesting that in both these examples protecting offspring or protecting mate this is not aggression for the sake of it but aggression that would aid survival of the genes
7
Q
define EEA
A
- environment of evolutionary adaptedness
- conditions that occurred in the environment at the time that a species was adapting in response to (eg industrialisation)
- eg when humans lived in hunter-gatherer groups
8
Q
define mutation
A
- change in genetic structure of an animal or plant that makes it different from others of same kind
9
Q
how does EEA explain behaviour?
A
- in historical times, people would go hunt for food in order to gain energy
- now, this is the driving force behind the obesity pandemic
10
Q
what does survival of the fittest mean?
A
- we are the best we can be because of evolution
- helpful traits helped our ancestors survive and have kids
- unhelpful traits weren’t passed on
- only the fittest traits stayed through reproduction
11
Q
how can aggression be explained by natural selection?
A
- aggression helped protect offspring and mates
- this made it more likely for genes to survive
- it wasn’t random aggression, but aggression that helped with survival
- supports the idea of natural selection
12
Q
how are infidelity, jealousy, and aggression linked to evolution?
A
- jealousy can lead to aggression when a mate is threatened
- males had to compete to pass on their genes
- aggression helped protect or guard a female from rivals
- males who defended their mates were more likely to reproduce
- jealousy and aggression were useful for survival of genes
13
Q
evidence: Buss and Shackleton
A
- looked at what men do when they feel threatened in a relationship
- men often give the female what she wants and act aggressively towards other males
- both actions help protect the male’s genes by stopping rivals and keeping the female
- women also act to protect their genes by keeping the relationship
- however, women may use verbal threats or say things like ‘he is taken’
- they may also threaten to leave if the man is unfaithful
- this works because women know their baby is theirs, but men need to make sure the child is theirs too
14
Q
evidence: Dobash and Dobash
A
- found violence against women often came from partner jealousy
- sexual jealousy can lead to aggression
- this supports the idea that aggression helps protect a male’s genes
- gives evidence for natural selection linking aggression to survival of genes
15
Q
what are the evolutionary reasons for aggression?
A
- to gain territory and resources e.g. bullying, mugging, warfare
- to defend against attacks and protect status and fitness
- to harm same-sex rivals in competition for mates and resources
- to gain status and dominance in social groups e.g. gang violence
- to deter rivals from future aggression by building a fearful reputation
- to prevent infidelity and make sure offspring are theirs e.g. domestic violence
16
Q
what is jealousy?
A
- an emotional response
- happens when there’s a risk of losing affection or status
- often linked to fear of losing a mate or social position
17
Q
what is infidelity?
A
- unfaithfulness of sexual partners
- when one partner has a sexual relationship outside of the committed relationship
18
Q
what is sexual infidelity?
A
- any behaviour involving sexual contact
- e.g. kissing, touching, sexual intercourse outside the committed relationship
19
Q
what is emotional infidelity?
A
- forming an affectionate attachment to another person
- can involve flirting or intimate conversations outside the committed relationship
20
Q
why do men express jealousy different to women?
A
- men need to compete with other males for access to choosy females
- lower status men take greater risks using aggression to avoid genetic extinction
- if the female is unfaithful, the male faces paternity uncertainty
- males cannot risk investing in offspring that aren’t their own
- this leads to more jealous and violent aggression towards rivals and the female
- aggression is stronger if the female is young and reproductively valuable
21
Q
why do women express jealousy different to men?
A
- if a male is unfaithful, the female risks losing time, resources, energy, protection, and commitment to her children
- females can always be sure their offspring are theirs
- they compete with other females for the quality of men, not their availability
- women take fewer risks with violence and use more indirect forms of aggression
22
Q
evidence: male male aggression
A
- Daly and Wilson: cross culturally, human violent aggression and homicide is more common in males, against other males
- Daly and Wilson: homicide more common in poor and unmarried men than richer, married ones
- sexual jealousy = more male male homicides than female female
23
Q
evidence: female female aggression
A
-
Buss and Dedden: female aggression more verbal against other females in order to maintain status and reduce attractiveness of competitors
- use verbal criticism to comment on physical appearance of other females and their promiscuity (for men looking for long term males with sexual fidelity) to lower their appear in eyes of men
24
Q
what is another reason of aggression? (limited resources)
A
- fighting over limited resources eg food and shelter
- those who successfully defended food and shelter would survive longer and reproduce
- any such behaviour can be inherited as genes leading to such aggression would survive
- Lorenz: aggression is evolved trait, particularly in males, to fight over limited resources
25
what is another reason of aggression? (being seen as stronger)
- **aggressive** humans and those seen as **stronger** in social group are more likely to survive
- if they’re **’higher’** in group or not attacked due to being seen as stronger, it puts them in good position with regard to pass on their genes
26
what are the strengths of evolution as an explanation for aggression?
- **theory of natural selection**: can explain aggression in humans. therefore, there’s **credibility** (ample evidence) eg **Kettlewell’s** study on moths (how they adapted to aid survival)
- scientific method used in research looking at theory. **Darwin** took careful **observations** and observed visible behaviour, which can be confirmed by others. there’s **scientific credibility**
27
what are the weaknesses of evolution as an explanation for aggression?
- aggressive person may **protect offspring** and therefore protect genes as theory of natural selection predicts. however, by being aggressive, they may be put at **risk**. they might **attract aggression** in others. by using energy on aggression they may not use limited resources well and might not survive
- if one theory explains behaviour, it can be used as criticism of different theory explaining same behaviour. eg **frustration aggression theory** suggests aggression in humans come from **frustrations** from environmental influences (alternative to theory of natural selection)
28
what are the links between male brain structure testosterone and behaviour? (different theory)
- **male brains** have small **structural differences** from female brains
- **higher testosterone levels** before and after birth affect **brain development**
- linked to traits like **spatial awareness and aggression**
- these traits helped **survival** in the environment of evolutionary adaptation **(eea)**
- **testosterone** linked to aggression
- **Mazur**: found more **inter-male fighting at puberty** when **testosterone increases**
29
what is a key limitation of evolutionary explanations for behaviour? (other things)
- evolutionary theories are **'post hoc'** made after the fact
- hard to scientifically test or prove
- limited **fossil evidence** for behaviour
- we can’t directly study the environment of evolutionary adaptation (eea)
- ideas may make sense but **aren’t empirically testable**
