Chapter 2: Evolutionary explanations for behavior

Question 1

Evolution and the modern theory of evolution

Answer 1

the process by which organisms change from generation to generation as a result of a change in heritable characteristics. Evolution can help explain behavior, in the sense that genes code for behavior, changing physical and mental traits, which can be genetically inherited as a result of responses to the environment – therefore, evolution can explain certain behavior and why they are the way they are.

The modern theory of evolution is based on the following:

• Biological organisms are driven by the need to survive and reproduce.
• Differential fitness: when organisms with different traits have adapted to their environment.
• Survival of the fittest: organisms that have adapted have higher chances of survival.
• Natural selection: less adapted organisms stop passing on their genes.

Question 2

Curtis, Aunger, and Rabie (2004)

Answer 2

suggested that disgust evolved as protection from the risk of disease. Researchers reasoned that if this was true, the following condition would have to be fulfilled:

• disgust should be felt more strongly when faced with a disease-salient stimulus
• disgust should operate in a similar way across cultures
• disgust should be more pronounced in females (have to protect babies)
• disgust should become weaker as the individuals age (don’t have to protect babies anymore)
• disgust should be stronger in contact with strangers.

Researchers made a survey with questions where participants had to (answer where they were from, age, gender, etc.) rate how disgusting certain images were. All five conditions were fulfilled, which supports the evolutionary explanation of disgust as a response that reduces the risk of disease.

Question 3

Chiao and Blizinsky (2010)

Answer 3

use an evolutionary perspective to explain the low prevalence of depression in collectivistic cultures, and concluded that the collectivist genetic values have evolved and opposed the susceptibility to depression.

Question 4

Kin selection theory proposed by Hamilton (1964)

Answer 4

explains altruistic behavior observed in animals and humans. It explains that an increase in the survival of an organism’s genes rather than the individual makes it more likely that organisms will help relatives more than strangers (e.g. trolley problem with them dutchmen).

Question 5

LeDoux (1996)

Answer 5

described two physiological pathways of emotions; namely, processing fear stimuli. The fast pathway goes through the thalamus and amygdala, the slow pathway also involves the structures of the hippocampus and neocortex. The evolutionary explanation for the influence of emotion on cognition and behavior links to natural selection, that organisms might either in a fast or slow manner – in sudden, stressful situations, an organism is required to act quickly rather than deeply think about the situation.

Question 6

Harlow’s studies (1958)

Answer 6

used animal model and studies of behavior – that an organism maximizes its chances of survival through staying close to an attachment figure in unfamiliar and possibly dangerous situations, as well as venturing outside and exploring developing necessary skills.

Question 7

Shaver and Hazan’s (1988)

Answer 7

shows parallels between attachment styles in childhood and later adult relationship patterns in humans.

Question 8

The theory of mind

Answer 8

the ability to recognize the beliefs and intentions of others, which is possibly only present among humans. Much of insight into this ability has derived from animal studies, and it is possible to trace the evolution of this ability by comparing the performance of animals (e.g. Call and Tomasello (2008))

Question 9

Limitations of evolutionary explanations of behavior

Answer 9

We cannot be sure of the true purposes of certain behaviors as we can’t go back in time!!!