Evolution and Nature vs Nurture

Psychology studies the mind and behavior of humans.
Neurons affect behavior and feelings.
The brain affects behavior and feelings.
Focus on the effect of biochemistry in the body and blood on behavior and emotions.

Charles Darwin: Discussed natural selection.
Darwin's observation: Different bird species inhabited different islands in the Galapagos.
Question: Why is there a particular bird species on a particular island?
Conclusion: The environment shapes physical attributes that evolve to match the environment.
Adaptive traits: Physical attributes that are suitable for a certain environment.
Example: Bird beaks
- Beak size and shape influence the type of food a bird can consume.
- Large cactus finch: Able to bite hard nutshell food.
- Other finches: Able to reach into little holes.
If a bird's physical attributes do not match the environment, it cannot consume the food available and will die.
Nature selects which species can survive: $Natural\ Selection$
Natural selection: The continuation of adaptive traits.

Survival of the fittest: Fitting with the environment, not necessarily the strongest.
Example: Tiger vs. Mouse
- A tiger may not survive if the environment does not provide any refuge, even though it is stronger than a mouse.

Lucas example: Lucas, at a few months old, reacts to his uncle's (the speaker’s brother) changed voice on the phone.
The speaker's brother automatically raises his voice when talking to Lucas.
Evolutionary benefit: Innate behaviors may have an evolutionary benefit.
Raising voice: May make Lucas less afraid. Lucas may also assume this is a woman.
Woman: The milk provider, therefore has a benefit to keep Lucas alive.
Lucas's brain is still developing and he reacts automatically.
Instincts: Lucas has instincts such as crying to keep him alive.
Behaviors: Help individuals or species to survive.
Psychologists: Interested in behaviors such as mating.

Symmetrical faces: More attractive because they predict healthy genes.
Healthy genes: Important for the survival of the fittest.
Mating with a partner with healthy genes: Increase the chances of having a healthy child.

Interested in survival of the species and survival of the fittest.
Study adaptation and natural selection in connection with mental processes and behaviors.
Dog behavior example: Dogs walk in circles before they lie down.
Survival benefit: Looking for predators and flattening the grass to hide from predators.
Innate behavior: Even if the behavior may not be as useful anymore, the instinct remains.
Kissing: Can lead to arousal and sexual arousal which can lead to reproduction which is important for the survival of the species.
Kissing brings you closer to a person: Physical proximity allows you to smell the person and detect pheromones.
Pheromones: Help you identify a suitable partner.

Fight or flight: Hormones activate the body to help you run away or fight.
Nowadays: Stressors are often not physical threats, but the body reacts in the same way.
Body posture: Even in arguments, people tend to make themselves big and raise their chin.
Exam anxiety: The body prepares for a fight, even if there is no physical threat.

Behavioral genetics and the nature vs nurture debate: How much of who you are is defined by nature (biological genetic makeup) and how much is defined by nurture (how you were raised).
Intelligence example: How much of your intelligence is innate and how much is learned.
Talent: You may be born with a certain talent in math or language.
Flexible brain: Synapses between neurons allow neurons to reconnect.
Neurons: Nerve cells that transmit information.
Gifted singer: Born with a talent but needs to practice to excel.
Shy person: Someone who is born to be shy may stay shy but needs to put more effort into overcoming shyness.

Twin studies: Used to study the relationship between nature and nurture.
Advantage: Twins have the same genetic makeup.
Similarities: Twins raised apart may still show similarities in personality, temperament, job interest, and social attitudes.
Minnesota study: 56 pairs of identical twins raised in different homes showed similar personality traits, temperament, job and leisure interests, and social attitudes.
Limitations: Small sample size and difficulty in finding twins raised apart.
Conclusion: Genes play an important role in combination with environmental factors.