Evolution & Behaviour Psychology Flashcards
1
Q
Brain size
A
- 6 million years ago we have experiences a 3-fold increase in brain size from earliest human ancestors
- Our brains are around 3 times larger than would expected to be for an animal our size
2
Q
Charles Darwin (1809-1882)
A
- Changed the way we look at evolution over time
3
Q
Observations before Darwin
A
- Change of species took place over time
- Characteristics have purpose
> e.g. porcupine spines have spikes to defend against predators
4
Q
Darwin set out the explain
A
- Why did changes take place
- How did new species emerge (speciation)
- What are the function of the [arts/characteristics
5
Q
Darwin’s ship journey in 1831
A
- Visited the Galapagos Island and discovered several species of Finches
- Seen they had similar characteristics
- Helping to develop his theory of natural selection
6
Q
Natural selection
A
- Basic mechanism of evolution
7
Q
On the origin of species (Darwin, 1859)
A
- Competition
> Populations can grow exponentially, but resources are limited
> “struggle for existence” - Variation
> Individuals vary in their ability to compete
> inevitable selection of individuals with the most advantageous variations
> Individuals best adapted to their environments are more likely to survive - Heritability
> Variation is heritable
> Differential reproductive success leads to a progressive evolution of particular populations (CHANGES)
8
Q
Natural selection involves
A
- Competition
- Variation
- Heritability
9
Q
Co-discovery of natural selection
A
- Alfred Russel Wallace (1823-1913)
- Both Darwin and Wallace worked together on natural selection
10
Q
Natural selection scrutinised
A
- Do populations really grow exponentially
> Yes - Has there been enough time?
> Yes - Is variation heritable
> Darwin wasn’t sure as he didn’t know genes existed
> Discovery of genes/genetic inheritance
11
Q
Genes
A
- Contain the information our bodies need to make proteins
- Influences what we look like on the outside and how we work on the inside
- Genes contained on strands of DNA
12
Q
DNA stand for
A
- Deoxyribonucleic acid
13
Q
Proteins
A
- Form the structure of our bodies, as well playing an important role in the processes that keep us alive
14
Q
Mendel (1856 - 1863)
A
- First person to describe genetic processes
- Said organisms contained 2 versions of a gene (1 from each parent)
- DNA is replicated and passed on to offspring
15
Q
3 processes that can make genetic variation
A
- Sexual reproduction
- Mutation
- Genetic drift (genes just disappear)
16
Q
The “selfish” gene
A
- The gene is the unit of selection > NOT characteristic > NOT individual - Genes are self-interested > as there goal is to be passed on - Fitness
17
Q
Fitness
A
- Numbers of copies of genes passed on to future generations
18
Q
Sexual dimorphism
A
- When females and males look different including reproduction systems
19
Q
Sexual selection
A
- Females and males face the same survival challenges but can look different
- Mating/reproductive advantage
20
Q
2 types of sexual selection
A
- Intersexual selection
- Intrasexual competition
21
Q
Intersexual selection
A
- Members of one biological sex choose a member of the opposite sex to mate with
- Usually ‘female choice’
22
Q
Intrasexual competition
A
- Physical combat
- Status, hierarchy
- Indicate greater resources
23
Q
Homo sapiens
A
- 200,000 years ago
24
Q
Cognitive revolution
A
- 70,000 years ago
- Modern language, religion, trade
25
Agricultural revolution
- 12,000 years ago
26
Industrial revolution
- 200 years ago
27
Sapiens lived as
- Foragers
- Collected wild plants and pursed wild animals
- Nomads (built in temporary shelters and followed food)
- High levels of physical activity
28
Sapiens lived
- In groups that consisted of several families
- Probably egalitarian social structures (no social hierarchy)
- Division of labour common
- High child mortality, bit long life possible
29
Evolution, genes and psychology intimately linked
- Thinking and behaviour depends on physiology (brain and body)
- Genes determine physiology and behaviour
30
Human psychology in the context of evolution: evolutionary psychology:
- Evolved biological and psychological mechanisms influence behaviour (aggression, cooperation, mate choice)
31
All behaviour is
- Interaction between psychological mechanism and environmental input
32
Jealousy
- Jealousy is psychological evolved mechanism
| - Contextual input (e.g. infidelity) triggers it
33
Fear of spiders
- Evolved because spiders presented threat to our survival
| - No longer likely to kill us, but mechanism still there
34
Humans are designed to
- Solve adaptive problems in the here and now
| - Keeping warm, food, protecting
35
David M. Buss
- Humans not designed to understand causal (evolutionary) processes that created our psychology (time frame of hundreds of thousands of years)
- Blind to our own adaptations: that hinder our understanding of our evolutionary processes
36
Essentialism
- Species are stable and have unchangeable "essences"
37
Teleology
- Misattributing desires, motives and intentions to inanimate objects and organisms
- e.g. "the sun is trying to come out"
38
Evolutionary psychology
- Scientific meta-theory to understand human nature
39
Adaptations
- Functional products of natural or sexual selection
40
The physiological and psychological mechanism that make up our behaviour is
- Known as adaptions
41
Physiological mechanism example
- Calluses
- The fixed skin you get on your body
- e.g. if you walk a lot you'll get thicker skin on your feet
42
Principles of evolutionary psychology
- Brain is an information processing device, produces behaviour in response to external and internal inputs
- Brain's adaptive mechanism were shaped by natural and sexual selection
- Different neural mechanisms are specialised for solving problems in humanity's evolutionary past
- Brains has evolved specialised neural mechanisms that were designed for solving problems that recurred over deep evolutionary time, giving modern humans stone-age minds
43
Fear adaptations
- Fears and phobias of evolutionary ancient dangers far more common than evolutionary modern dangers
44
Evolutionary ancient dangers
- e.g. Snakes and spiders
45
Evolutionary modern
- e.g. Cars and guns
46
Snakes and spiders (fear)
- Snakes and spiders signal potential threats to survival (poison)
- So humans had to evolve fear adaptations to survive
- Well supported by research
- Automatic and cant be stopped if you see one
- Shown in infants (physiological arousal) - pupil size increased when seen S & S instead of fish when shown photos
47
Cars and Guns (fear)
- Less common
- Although more dangerous to survival in modern environment
- Not enough time for evolution to adapt to modern environment
48
Depression
- More than 300 million people globally suffer from it
- Serious health condition and disability
- Symptoms: lasting feelings of unhappiness & hopelessness, losing interest in things usual enjoyed, tired and no appetite
49
Depression - Theories
- Depression as an adaptive response
- Modern social environment differs from past: greater inequality loneliness
- Modern populations: overfed, malnourished, sunlight-deficient, sleep-deprived
- Contributes to poor physical health (chronic disease) and depression
50
Eating behaviour: Unhealthy
- Major contributor to health problems (obesity, diabetes, heart disease, cancer)
- Cravings for food that are high in sugar and fat (energy-dense)
51
Eating behaviour: Sugar
- Evolutionary past
- From fruit or honey
- Not possible to get too much sugar
52
Eating behaviour: Fat
- Evolutionary past
- Game animals lean
- Not possible to get too much fat
53
Modern world on food
- Markey economy produces immense amount of food
> access to well-fed animals
- access to all kinds of sugars
54
Ancestral conditions and the modern world (eating behaviour)
- Mismatched
| - Adaptions that were reproduction-supporting now cause problems
55
Sex differences
- Evolved sexual differences exists:
> women and men differ in domains where they recurrently faced different adaptive problem
> Women and men are expected to be similar in all domains in which they have faced similar adaptive problems during evolution
56
Men and Women sex differences
- SIMILARITIES OUTNUMBER THE DIFFERENCES
57
Sex Differences: Women (adaptive)
- Faced adaptive problems of pregnancy and breastfeeding (metabolically expensive)
58
Sex Differences: Men (adaptive)
- Faced adaptive problems of paternity uncertainty and misdirected parental investment
59
Women ≠ men
| sex differences
- Number of offspring that each sex can possibly produce
- Obligatory parental investment
- Reproductive uncertainty
60
Both sex
| sex differences
- Both face problems of identifying mates who will commit long-term
- (seeking signs of love as commitment device)
61
Cooperation
- Evolved adaptation to increase reproductive success of social partners
- Inclusive fitness
- Driven by reciprocity
> we will receive benefits in return
62
Inclusive fitness
- Genes of relatives are passed on (including shared genes)
63
Sapiens Cooperation
- Developed large-scale flexible cooperation
- Potentially made possible through unique language
- Cooperative breeding
64
Cooperative breeding
- (help) raising offspring of others
65
Human aggression
- Humans have long evolutionary history of violence
- Adaptive problems of social living
- Secure resources from others
- Defend against attack
- Inflict costs on same-sex rivals (access to females)
- Physical aggression often form of intra-sexual competition
66
Common criticisms of evolutionary psychology
| political and ethical issues
- Eugenics
- Feminism
- Naturalistic Fallacy
- Panglossian
- Genetic Determinism
- Ancestral environment
67
Common criticisms of evolutionary psychology
(political and ethical issues): Eugenics
- Improve genetic quality of human population by excluding “less desirable” genetic groups and promoting “superior” genetic groups
- Selective breeding in humans
68
Common criticisms of evolutionary psychology
(political and ethical issues): Feminism
- Detrimental to achieve gender equality
69
Common criticisms of evolutionary psychology
(political and ethical issues): Naturalistic Fallacy
- “ought cannot be derived from is”
| - No connection between what is biologically or naturally selected and what is ethically right or wrong
70
Common criticisms of evolutionary psychology
(political and ethical issues): Panglossian
- Just-so-Stories
| - Difficult to verify
71
Common criticisms of evolutionary psychology
(political and ethical issues): Genetic Determinism
- Belief that human behaviour is controlled by an individual's genes
- Importance of non-genetic and non-adaptive explanations
72
Common criticisms of evolutionary psychology
(political and ethical issues): Ancestral environment
- Large uncertainty about the ancestral environment
73
Parasite Theory
- Parasites account for more mortality than anything else (Hamilton & Zuk: 1982)
- Signalling a strong immune system should be attractive
74
Parasite Theory - Swallow example
- Length and symmetry of barn swallow's tail streamers signals parasite load and immune function
- Females prefer long tailed males
75
Averageness Hypothesis
- Average/ composite faces rated as more attractive than the originals
- Due to average-looking people having fewer 'risks; associated with them
- Allows you to morph peoples faces into one
76
Parental investment theory created by
- Robert Trivers, 1972
77
Parental investment
- Investment in offspring by the parent that increases the offspring's chances of surviving and hence reproductive success
- At the expense of the parent's ability to invest in other offspring
78
Parental investment theory: Mating investment
- Sexual act
| - Sex cells (gametes)
79
Parental investment theory:
| Rearing investment
- Time and energy to raise offspring
80
Women's parental investment
- In both mating and rearing efforts greatly surpasses that of the male
81
Parental investment: 2 categories
- Mating investment
| - Rearing investment
82
Size of egg compared to sperm
- Gamete size of egg much larger than sperm
83
Parental investment theory:
| Sex that invest more
- Invest more in offspring will be more selective when choosing a mate
> usually females (but males are pickier in species where males invest more)
84
Parental investment theory:
| Sex that invest less
- Invest less will have intra-sexual competition for access to mates
> usually males (in species where parental investment is bigger for a male, females are more aggressive, brightly coloured, and larger than males)
85
Evolutionary approach to mate preferences
- David Buss, 1989
| - Influential article testing predictions from evolutionary psychology in 10,000 people from 33 countries
86
Sex differences in Mate Preferences
- Buss (1989)
- Males value reproductive capacity more than females
- Females value resource acquisition more than males
87
Age preferences
- Kenrick & Keefe (1989)
- Females
> from 20s up to roughly 60s tend to want someone their same age
> average 2 years younger and an average of 9 years older
- Males
> in their 20s prefer women in the 20s
> older males prefer younger females
88
Problems with EP approach
- HUGE intra-sexual variation in preferences
- Biased samples
- Social desirability
89
Sexual Dimorphism in the Face
- Distinct differences in size or appearance between the sexes of an animal in addition to the sexual organs themselves
90
Masculinity preferences
Perret et al. 1998
Rantala et al. 2012
- Women's preferences for sexual dimorphism in the male face are complicated
- High Testosterone:
> strong immune system
- Low Testosterone
> Weak immune response
91
Cycle Shifts
- Menstrual cycle alters face preference
- People had to rate their preference
- Women typically prefer feminised faces most of the time, but prefer slightly masculinised faces in the fertile phases
92
MHC
- Major histocompatibility complex
93
MHC compatibility - Species
- Genes that control the immune response and effective resistance against pathogens
- Involved in mate choice for many species through olfactory cues
- Preference for MHC-dissimilarity in potential partners
94
MHC compatibility: Humans (wedekind. 1995)
- Women asked to smell T-shirts worn by different males
- Women that were ovulating rated the odours of MHC-dissimilar men as more pleasant
- (reversed in women taking contraceptives)
95
Social roles: Evolutionary psychology
- Evolutionary adaptations
| > psychological sex differences
96
Social roles: Social psychology
Eagly & Wood, 1999
- Social structure
- psychological sex difference
- culture and social structure can influence behaviour
- individuals seek mate who is likely to be successful in their social role
97
Gender equality
- Gender differences in mate preferences decline with increases in nations’ gender parity (Zentner & Mitura, 2012)
98
Evolutionary vs Social psychology
EP: Sex differences in mate preferences stem from sex differences in relative gamete size and parental investment (e.g. Buss 1989)
SP: Sex differences in mate preferences stem from gendered social roles (e.g. Eagly & Wood, 1999)
