Evolutionary Perspectives PPT

Biological Basis of Personality - Evolutionary Theory

• Presenter: Dr. Sylwia Cisek (s.z.cisek@soton.ac.uk)

Charles Darwin

• Biological Evolution:

  • Changes in genetic and physical characteristics of a population over time.

• Evolutionary Psychology:

  • Examines how evolutionary history influences behavior patterns and cognitive strategies for reproduction and survival.

Explanations of Behaviour

• Ultimate Causes:

  • Long-term events shaping species behavior through generations (from Latin "ultimatus" = to come to an end).

• Proximate Causes:

  • Immediate environmental factors influencing behavior (from Latin "proximus" = near).

Natural Selection and Adaptation

• Adaptation:

  • The process of generations adjusting to environmental changes.

• Natural Selection:

  • Mechanism where beneficial variations are passed down, leading to evolutionary change.

Natural Selection Overview

• Key Concepts:

  • Variability among individuals (random mutation)

  • Inheritance of advantageous traits

  • Differential reproduction rates contribute to evolutionary fitness.

• Example:

  • Faster wolves have higher chances of survival and reproduction than slower ones, changing the population over generations.

Giraffe Example

• Giraffe Neck Evolution:

  • Giraffes with longer necks survived better in the struggle for resources, leading to modern long-necked giraffes through generations.

Genotype and Phenotype

• Survival of the Fittest:

  • Only the best adapted phenotypes and genotypes survive due to competition for resources.

Sexual Selection

• Overview:

  • Natural selection focused on traits related to mating success.

Sociobiology

• Definition:

  • Systematic study of biological bases for all social behavior.

• Focus:

  • Investigating evolutionary roots of contemporary social actions, especially concerning reproduction and parenting.

Male Attractiveness Traits

• Key Characteristics:

  • Height

  • Broad shoulders/slim waist ratio (ideal ~0.75)

  • Muscular chest

  • Physical traits associated with normal testosterone levels: broad jaw, strong brow

Female Attractiveness Traits

• Key Characteristics:

  • Low waist-hip ratio (~0.70)

  • Cues of youth: full lips, clear skin, lustrous hair, symmetrical face, round breasts

Mate Selection Dynamics

• Health of Offspring:

  • Men tend to desire younger mates while women prefer older partners.

• Differential Parental Investment:

  • Females face greater consequences of childbearing, making them more selective in mate choice.

Preferences in Mate Choice

• Women’s Desires:

  • Economic stability

  • Social status

  • Ambition, dependability, intelligence, compatibility, love, commitment, physical strength, health

• Men’s Desires:

  • Youth, beauty indicating health and fertility, fidelity

Infidelity Perspectives

• Men's View:

  • Concerned with sexual infidelity due to paternity certainty

• Women's View:

  • Concerned with emotional infidelity, perceiving it as a signal of diversion

• Differences in Responses:

  • Men likely break up over sexual infidelity; women over emotional infidelity.

Altruistic Behaviour

• Concept:

  • Behaving selflessly, despite potential genetic or reproductive disadvantages.

• Inclusive Fitness:

  • Natural selection favors gene replication through indirect means, such as aiding relatives (kin selection).

Evolution and Trait Theory

• Social Nature of Humans:

  • Humans live in groups, and certain personality traits facilitate cooperation and problem-solving.

• Environmental Success:

  • Different traits may lead to success depending on environmental contexts.