What does evolutionary theory explain?
How diverse life forms came to exist and the characteristics of human nature
- stresses the importance of biological force on the direction of change
Uniformitarianism
Changes in the earth are caused by continuous and uniform processes
Proposed by Charles Lyell
Natural selection
Organisms adapt and change as a result of their environment
Biological forces that push for adaptation
Harsh environment
# of offspring
Variability from mutations
2 aspects of evolutionary theory
- Species go through gradual change over a long period of time
- Breaking away from an original group to establish a new branch in the phylogenetic tree
Define inclusive fitness
Fitness that extends to the next generations reproductive success
Phenotypic plasticity
The ability to produce different phenotypes when faced with different environmental challenges
Nomological network of evidence
Convergence of many evidence sources to evaluate evolutionary theory
Evolution of humans
Homo habilis - 1.9 to 1.8 million years ago
Homo erectus - 1.8 million to 300,000 years ago
Modern humans - 200,000 years ago
Unique human features
- Common body shape and specific organs
- Mate and produce offspring
- Bipedalism
- hand use for tools, carrying, communication, etc - Manipulation of tools
- More reliance on sight than smell
- Long pre and post-natal development
- Social belonging
- Ability of the human brain
- Consciousness
- Theory of mind
Ethology
Study of the causes of behaviour, the effect of genetics and learning, adaptive significance, and evolutionary history
Behaviours are…
Innate
What are behaviours supported by?
Integration of brain regions, physiological responses, and motivation
Fixed/modal action patterns
Innate behaviours that are more complex than reflexes and are elicited by the releasing stimulus
Ex. Birds building nests
Attachment behaviour vs caregiver system
Reflexes and behaviours that elicit caregiving behaviours from adults
Infant behaviour is to stay as close to the caregiver for protection
Caregiver behaviour is to respond to infant signals
Attachment behaviour system
Reflexes and behaviours that elicit caregiving behaviours from adults, which shape the infant and their caregiving expectations
Evolutionary psychology
Using the principles of evolution to understand the human mind
Complex machines that solve problems faced by our ancestors and adapted through natural selection
Adaptations lead to the development of development of special abilities
What are adaptive problems
- influence survival and reproductive success
- occurred many times in evolutionary history
- solutions have an impact on humans reproductive success
3 stages of life in evolutionary theory
- Healthy growth and development
- most vulnerable - Mating and conception
- Effective parenting
Stages if attachment
Stage 1 - birth to 3 months
Maintain closeness with caregivers
Development of predictable behaviour
Caregiver expectations are formed
Stage 2 - 3 to 6 months
More responsive to familiar figures
Actively seek interactions with caregiver
Stage 3 - 6 to 9 months
Physical proximity
Contact with objects of attachment
Explore environment
Stage 4 - 9 to 12 months
Internal mental representation of objects
Expectations about caregiver responses
The strange situation
Procedure used to identify differences in attachment relationships
Secure attachment
- infants explore environment
- engage with strangers when caregiver present
- seek interaction and greet caregiver after separation
- caregiver calms infants down
- caregiver is accessible and responsive to the infant
Anxious avoidant attachment
- avoid contact with caregiver
- disregard attempts to engage with after separation
- less distress when alone
- caregiver is emotionally unavailable and unresponsive
- infant is self-sufficient and independent
Anxious-resistant attachment
- cautious around strangers
- stop exploring when caregiver departs
- angry at caregivers return but seek closeness
- inconsistent and unpredictable caregiving
