UNIT 3: BIOLOGICAL LEVEL OF ANALYSIS

Day 12: Evolutional Aspects

Outcome(s):

Discuss through a Socratic seminar the extent to which genetics influence behavior

Examine evolutionary explanations of behavior to utilize as evidence in a Socratic seminar

Discuss ethical considerations in research into genetic influences on behavior

Agenda:

1. Warm Up2. Guided Notes: Evolution & Biological

LoA3. Discussion on the role of genetics and

evolution on our behavior: why do men cheat on their wives?

Develop Discussion Questions Socratic Seminar

4. ERQ – Evolution & Biological LOA

Warm Up

Thinking Map: Evolution & Biological Level of Analysis

Theory of Evolution & Charles Darwin

Theory of evolution: those who adapt best to the environment will have a greater chance of surviving, having children, and passing on their genes to their offspring

Theory of natural selection: those members of a species who have characteristics which are better suited to the environment will be more likely to breed, and thus to pass on these traits

On the Origin of Species – the theory of adaptation: the result of natural selection is that the species develop characteristics that make it more competitive within its own environment

Studying Evolution

Professor Tetsuro Matsuzawa (2007) Kyoto University in Japan Aim: to examine spatial memory in young chimps Methods: three pairs of chimps, taught to recognize numerals 1-9 on

computer monitor Chimps and human participants later seated at a computer terminal

where numerals flashed on a touch-screen in random sequence. The participant had to remember which numeral appeared in which location, and touch the squares in the appropriate sequence.

Human participants made many errors, accuracy decreased as numbers replaced with blank squares more quickly

Chimps had remarkable memory for spatial distribution with no difference shown for shorter durations

Why? Psychologists argue that it is a necessary adaptation for chimps to have this type of memory so that they can remember where food (and dangers) are in the rainforest

http://www.youtube.com/watch?v=fzUyX5kezb0

Evolutionary Psychology

Grounded in the principle that as genes mutate, those that are advantageous are passed down through a process of natural selection

Attempts to explain how human behaviors can be a testimony to the development of our species over time

Studying Evolutionary Psychology

Dan Fessler Research at University of California

at Los Angeles (UCLA) on disgust (2006)

Main argument: emotion of disgust allowed our ancestors to survive long enough to produce offspring, who in turn passed the same sensitivities on to us

Investigated nausea experiences by women in first trimester of pregnancy Infusion of hormones lowers the

expectant mother’s immune system so as to not fight the new foreign genetic material in her womb

Hypothesis: nausea response helps compensate for the suppressed immune system

Methods: 496 healthy pregnant women between

the ages of 18-50 and asked them to consider 32 potentially stomach sickening scenarios (ex: stepping on a worm barefoot, fish hook in finger, maggots on meat in trash can)

First asked questions about questions to see if they were first experiencing morning sickness

Then they ranked how disgusting each scenario was

Findings/Discussion: Women in 1st trimester scored much

higher in disgust sensitivity When controlled for morning sickness, the

response only held for disgusting scenarios involving food, such as the maggot example

Natural selection may have helped compensate for the increased susceptibility to disease during the risky period in pregnancy – disgust is a form of protection against disease

Studying Evolutionary Psychology cont.

Curtis et al. (2004) To test whether there were patterns in people’s disgust

responses Method/participants:

77,000 participants in 165 countries Used an online survey in which participants were shown 20 images

and to rank level of disgust Among the 20 images were 7 pairs where one was an infection or

harmful to the immune system and the others visually similar but non-infections

Findings/Discussion: The disgust reaction more strongly elicited for those images that

threaten one’s immune system Disgust reaction decreased with age (disgust reactions higher in

younger people) Once again… this supports the idea of disgust as a key to successful

reproduction

Things to consider when examining an evolutionary argument (limitations):

Since it may be difficult to test empirically some evolution-based theories, researchers may be susceptible to confirmation bias—that is, they see what they expect to see

Little is known about the behavior of early Homo sapiens, so statements about how humans “used to be” are hypothetical

Evolutionary arguments often underestimate the role of cultural influences in shaping behaviors

Ethical Considerations when Researching Genetic Influences on Behavior Hereditary diseases Genetic information obtained from research can be problematic

for the participant’s family If misused, genetic information can be stigmatizing and may affect

people’s ability to get jobs or insurance GATTACA: http://www.youtube.com/watch?v=ZppWok6SX88

Privacy and confidentiality Informed consent Can reveal unexpected information that may harm research

participants and create undue stress Evidence of misattributed paternity Unrevealed adoptions Carries a gene for a genetic disorder

Some groups may have objections to genetic study as a cultural principle

Helen Fischer’s Research on Love

Participants 32 people madly in love in

fMRI 17 in love was accepted 15 in love who had been

dumped When you fall in love

A “special meaning” and focus on a person

Intense energy Dependence Sexually possessive –

Darwinian purpose? Main characteristics of

romantic love: craving, motivation, obsession

Questioning the participants: What percentage of the

day/night do you think about this person?

Last question: would you die for him/her?

Methods fMRI Brain scans –

sweetheart, distractor/neutral, and control

Findings/Discussion Same brain region activated

that is activated when on cocaine

Evolutionary aspect of love: sex drive, romantic love, attachmenthttp://www.ted.com/talks/helen_fisher_

tells_us_why_we_love_cheat.html play until ~7:50

From Day 6

Reading

Read The Biology and Psychology of Cheating

When you are done reading… consider the following question:Why do men cheat on their wives?

On a notecard, write: One thing from the article you might agree

with One thing from the article you might

disagree with Two questions to discuss with classmates

Discussion

Discussion Rules1. No raising hands2. Don’t talk over others3. It is a discussion for learning, not a debate

Debrief

Possible SAQ/ERQ:Examine one evolutionary explanation of

behaviour

Directions: with a partner, create an outline for this ERQ and write the topic sentences of each paragraph

Looking Ahead: