Behavior and Genetics

Question 1

Comparison of monozygotic versus dizygotic twins, each raised in the same household
Tries to distinguish between nature and nurture for a trait

Answer 1

Classical twin study

Question 2

Monozygotic vs dizygotic twins

Answer 2

Monozygotic: identical twins from one egg, have 100% the same genes
Dizygotic: fraternal twins from two eggs, share 50% of genes

Question 3

Problems with twin studies

Answer 3

Identical twins are treated more similarly than fraternal twins, meaning that monozygotic twins have more similar environments compared to dizygotic twins

Question 4

Adopted child is compared to biological family and adopted family, allowing researchers to assess influence of nature versus nurture

Answer 4

Adoption studies

Question 5

Strong genetic component findings of twin and adoption studies

Answer 5

Identical twins are more similar, fraternal twins are not
Identical twins raised together or apart have the same findings (meaning environment has little influence)
Adopted child findings more similar to biological than adoptive parents

Question 6

Strong environmental component findings of twin and adoption studies

Answer 6

Identical twins and fraternal twins have similar outcomes
Identical twins raised together have similar findings, whereas identical twins apart have divergent findings
Adopted child findings more similar to adoptive than bioloigical parents

Question 7

Behavior traits that are not present at birth but are acquired through experience with the environment

Answer 7

Learned behavior

Question 8

4 Characteristics of learned behavior

Answer 8

Non-inherited: acquired through observation and experience
Extrinsic: will be absent if organism is isolated
Permutable: can be changed through experience
Progressive: can change and improve over time

Examples of learned behavior:
Learning to read
Dog fetching a ball

Question 9

Function of behavior

Answer 9

To maintain homeostasis (equilibrium)

Question 10

The extent to which a trait or behavior aids survival and/or reproduction

Answer 10

adaptive value

Question 11

A field of study that focuses on the observation of animal behaviors

Answer 11

ethology

Question 12

Individual units of heredity
Specific segments of DNA

Answer 12

genes

Question 13

Traits that are linked to specific genes, like eye or hair color
Follow Mendelian monogenetic inheritance patterns
Interact minimally with environment

Answer 13

simple traits

Question 14

Traits that are associated with groups of genes, like intelligence
Follow Mendelian polygenic inheritance patterns
Subject to greater environmental influence

Answer 14

complex traits

Question 15

Temperament vs personality

Answer 15

Temperament is one’s innate tendency toward certain characteristics
Personality is a collection of characteristics believed to be constant over one’s lifetime

Question 16

Estimates the amount of variance of a trait that can be attributed to genes in specific subgroups of individuals

Answer 16

Heritability

For example, stating that intelligence (trait) has a heritability of 50% means that 50% of the difference in intelligence is accounted for by genes, NOT that intelligence is 50% genetic
Specific to the population being studied, and is NOT a broad estimate of nature vs nurture in a general population

Question 17

Genetically programmed behavior, present from birth, that requires no experience with the environment

Answer 17

Innate behavior

Question 18

4 Characteristics of innate behavior

Answer 18

Inherited: genetically programmed rather than learned

Intrinsic: present even if organism is isolated, does not require being taught

Stereotypic: performed the same way every time

Consummate: Fully developed, does not change with experience or environment

Examples of innate behavior:
Urination, defecation
Birds migrating at the same time every season
Shivering when cold

Question 19

Three main types of innate behavior

Answer 19

Reflexes = sensory and motor nerve loop response

Orientation behaviors = kinesis (undirected change in movement, like a change in speed) and taxis (directed change in movement, such as moving closer or further from a stimulus)

Fixed-action patterns = series of coordinated actions triggered by a key stimulus; similar to a reflex but more complex. Example: praying mantis strike manuever when encountering prey

Question 20

Types of behavior

Answer 20

• Innate behavior
  Inherited behavior that is genetically programmed and does not change through experience
• Learned behavior
  Acquired behavior that develops and changes with experience
• Complex behavior
  Combination of innate and learned behavior
  Requires a relationship between genes and environment in adaptation
  Example: Ability of humans to jump. All humans innately know this behavior, but through practice and adaptation can improve it
• Covert behavior
  Behaviors that are not observable
  Example: Ability of humans to dream

Question 21

Use of genetic methods to investigate the nature and origins of individual differences in behavior

Answer 21

behavioral genetics

Question 22

Passing of traits from parents/ancestors to offspring through genes

Answer 22

heredity

Question 23

Distinguishing qualities and characteristics of individuals

Answer 23

traits

Question 24

Qualities that are passed from parents to offspring, such as eye color, hair color, and height

Answer 24

inherited traits

Question 25

Learned traits that come from environmental factors, such as temper or happiness

Answer 25

Acquired traits