Evolutionary theories Flashcards
Biological evolution
changes that take place in the genetic and physical characteristics of a population or group of organism over time
evolutionary psychology
investigates how evolutionary history contributes to the development of behaviour patterns and cognitive strategies related to reproduction and survival during life
Charles Darwin
Developed the evolutionary theory
Explanations of behaviours
ultimate causes, proximate causes
ultimate causes
from the Latin ultimatus to come to an end
Events and conditions that over successive generations have slowly shaped the behaviour of our species
proximate causes
from Latin proximus = near
Immediate environmental variables that affect behaviour
adaptation
the ability of generations of species to adapt effectively to changes in the environment
natural selection
the process whereby some variations in species will be transferred from one generation to the next but others will not
variation
individual differences, in the behaviours they exhibit . This is partly due to variation in the genes
Adaptive behaviours
help an organism survive and reproduce
maladaptive behaviours
hinders survival and reproduction
ecological niche
if dangerous environment it may pay too be neurotic, lots of opportunities it may pay to be extroverted
Depends on environment
inheritance
genes transmitted from parents to offspring
competition
different sets of genes end up in competition with one another, for which best help the organism survive
Natural selection
variability within inheritance of traits and differential reproduction
Outlive and out produce other genes so live longer and reproduce more
natural selection process
- Some individuals have better characteristics
- Become stronger and healthier - fitter
- Have more offspring
- Next generation has a higher proportion of the better characteristics
- Many generations later, the whole species has changed to the new form
Evolutionary theorists assume
features related to the human cognition, motivation, personality and behaviour are the result of natural selection. They are adaptations, inherited solutions to the survival and reproduction problems posed by the environment
Phenotype and genotype interaction
over time, competition for food and other resources will allow only the best adapted phenotypes and their corresponding genotypes to survive
genotype
genetic make up that differs from all other organisms (except identical twins). Each genes have different alleles
phentoype
interaction of the genotype with the environment
Sexual selection
Traits that individuals possess that gives them an advantage over others in the competition for mates. Reduced survival of peacocks tail is compensated by increase advantage in reproduction
Sociobiology
the systematic study of the biological basis of all social behaviour sociobiologists are especially interested in understanding the evolutionary roots of our modern-day social actions, especially related to reproduction and parenting
male attractiveness
height, broad shoulders and slim waist - inverted triangle waist to shoulder ratio 0,75, chest muscularity, normal level of testosterone; broad jaw and strong brow
Female attractiveness
low waist-hip ratio: 0.7
Signals of fertility, physical health and not already pregnant, full lips, smooth skin, lustrous hair, symmetrical face, round breasts
Mate selection
maximising chances of healthy offspring, men want younger mates, women prefer older partners.
Differential parental investments - consequences of having a child is more for females than males, females are more selective in their choice of mates
- female have less ova than men sperm
- metabolic resources during pregnancy
- discomfort and risk of death in childbirth
- breast-feeding = more metabolic resources
People should try to select a mate who would maximise their chances of having healthy offspring
How do women assess their potential partner?
- economic resources
- social status
- ambition
- dependability and stability
- intelligence
- compatibility (potential for sustaining the relationship)
- love
- commitments
- size and strength
- good health
Ways to assess partner
- quality of genes - good health, intelligence, strength
- whatever they will devote resources to their children and not leave to produce children elsewhere
What do men want?
- youth
- beauty (health and fertility)
- faithfulness /fidelity
Men want to detect if their potential partner will provide them with a fast production of offspring and be faithful to them
Infidelity
men: sexual infidelity jeopardise paternity certainty
Women: emotional infidelity signal diversion to other women
Men breaks up if sexual infidelity and women break up if emotional infidelity
Altruistic behaviour
why individuals behave in an altruistic or selfless way may be contrary to own genetic or reproductive interest
Inclusive fitness
natural selection favours organism which maximise replications of their genes not only directly by reproduction but also indirectly by helping those with whom they share genes
kin selection
we are more willing to behave altruistically towards close relatives than towards strangers
Evolution and trait theory
chapter 9, humans are social creatures and live in groups
Certain personality traits allow members to cooperate to achieve goals and sort out problems
