1. LAY BELIEFS ABOUT HERITABILITY
AND HUMAN AGENCY
Emily Willoughby
Matt McGue
James Lee

2. OVERVIEW
Original motivation: look at attitudes about free will and determinism in a genetically-sensitive design
Sibling Interaction and Behavior Study (SIBS)
Pilot possible scales on MTurk

3. AGENCY AND GENES BACKGROUND
I am often asked, “Given your experience with identical twins reared apart, what is your feeling about determinism and free will?” This is an interesting question. Observation of similarity between twins reared apart constantly stimulated me to ponder the problem of genetic determinism. I am not prepared to even attempt to try to answer the question.
— Tom Bouchard, 1991

4. AGENCY AND GENES BACKGROUND
How do attitudes about free will and determinism relate to what people believe about the genetic and environmental contributions to human behavior?
How well do these beliefs align with empirical findings from published heritability estimates?
What influences do genetic and environmental factors actually have on beliefs about free will and determinism?

5. METHODS SAMPLE Two MTurk recruitment phases, total N = 1,041
Demographic criteria not significantly different between phases
Sample not population representative: More educated, more liberal, and less religious than general population

6. METHODS SCALES Free will and determinism
Free Will and Determinism Scale-Plus (FAD+; Paulhus and Carey 2011)
Free Will Inventory (FWI; Nadelhoffer, 2014)
Belief in Genetic Determinism scale (BGD; Keller 2005)
Belief in Social Determinism scale (BSD; Rangel and Keller 2011)

7. METHODS SCALES Social attitudes
Authoritarianism (SL-A; Duckitt et al. 2010)
Egalitarianism (SL-EG; Feldman and Steenbergen 2001; Feldman 1988)
Religiousness (9 MCTFR items)

8. METHODS SCALES Genetics
Genetics literacy (PUGGS; Carver et al. 2017; Haga et al. 2013)
Lay estimates of genetic influence on traits (LEGIT) were assessed from an adaptation of a section of the PUGGS questionnaire called the “table of traits”

9. METHODS SCALES Lay estimates of genetic influence on traits
“People vary in traits (physical features, behaviors, diseases and disorders) such as those shown in the table below. Both genetic factors and environmental factors contribute to differences among people. Environmental factors can for example include culture, upbringing, eating habits and exposure to pollution. For each of the characteristics below, indicate to what extent you think genetic and environmental factors contribute to differences among people.”

10. METHODS
SCALES

11. METHODS SCALES PUGGS ITEMS: NEW ITEMS: Eye color Blood group
Color blindness
ADHD
Height
Alcoholism
Violent behavior
Political beliefs
Diabetes
Schizophrenia
Intelligence
Depression
Bipolar disorder
Breast cancer
Obesity
Personality
Blood pressure
Athleticism
Heart disease
Musical talent
Sexual orientation

13. RATINGS FORMED CLUSTERS
FINDING 1:
RATINGS FORMED CLUSTERS
Genetic influence ratings across 21 traits showed distinct patterns of intercorrelation

15. RATINGS FORMED CLUSTERS
FINDING 1:
RATINGS FORMED CLUSTERS
Genetic influence ratings across 21 traits showed distinct patterns of intercorrelation
PCA supported a four-factor solution that explained ~50% of total variance

17. RATINGS FORMED CLUSTERS
FINDING 1:
RATINGS FORMED CLUSTERS
Genetic influence ratings across 21 traits showed distinct patterns of intercorrelation
PCA supported a four-factor solution that explained ~50% of total variance
Varimax rotation revealed cluster identities

18. RATINGS FORMED CLUSTERS
FINDING 1:
RATINGS FORMED CLUSTERS
Physical trait factor: Eye color, blood group, color blindness, height
Psychological trait factor: Intelligence, personality, athleticism, violent behavior, musical talent
Lifestyle trait factor: Obesity, diabetes, heart disease, blood pressure
Psychiatric trait factor: Bipolar disorder, schizophrenia, ADHD, and… sexual orientation?
Orphans? Political orientation, breast cancer

19. RATINGS PREDICT AGENTIC BELIEFS
FINDING 2:
RATINGS PREDICT AGENTIC BELIEFS
(Weakly.)

22. RATINGS PREDICT SOCIAL ATTITUDES
FINDING 3:
RATINGS PREDICT SOCIAL ATTITUDES
(Again… weakly.)

23. RATINGS PREDICT SOCIAL ATTITUDES
FINDING 3:
RATINGS PREDICT SOCIAL ATTITUDES

24. RATINGS PREDICT SOCIAL ATTITUDES
FINDING 3:
RATINGS PREDICT SOCIAL ATTITUDES

25. PEOPLE ARE PRETTY ACCURATE OVERALL
FINDING 4:
PEOPLE ARE PRETTY ACCURATE OVERALL
Compare meta-analytic heritability estimates for each trait surveyed on participants
Convert participant responses to percentage scale

27. PEOPLE ARE PRETTY ACCURATE OVERALL
FINDING 4:
PEOPLE ARE PRETTY ACCURATE OVERALL
Compare meta-analytic heritability estimates for each trait surveyed on participants
Convert participant responses to percentage scale
Correlation between participant responses and published estimates across traits is .77!

29. PEOPLE ARE PRETTY ACCURATE OVERALL
FINDING 4:
PEOPLE ARE PRETTY ACCURATE OVERALL
Compare meta-analytic heritability estimates for each trait surveyed on participants
Convert participant responses to percentage scale
Correlation between participant responses and published estimates across traits is .77!
Some people are more accurate than others… why?

31. PEOPLE ARE PRETTY ACCURATE OVERALL
FINDING 4:
PEOPLE ARE PRETTY ACCURATE OVERALL
Compare meta-analytic heritability estimates for each trait surveyed on participants
Convert participant responses to percentage scale
Correlation between participant responses and published estimates across traits is .77!
Some people are more accurate than others… why?
Accuracy difference score for each trait
Average these together for a rough single measure of accuracy for each participant

32. Accuracy scores without taking absolute value

33. WHAT DOES ACCURACY PREDICT?
FINDING 5:
WHAT DOES ACCURACY PREDICT?
Accuracy predicts:
Higher scores on Beliefs in Genetic Determinism (BGD) and Beliefs in Social Determinism (BSD) but no other measure of free will or determinism

34. A negative correlation indicates greater accuracy; i. e
A negative correlation indicates greater accuracy; i.e., less distance from the accurate estimate.
BSD: only due to stronger accuracy on eye color and blood group, weakly nonsignificant negatives on most traits
BGD: due to weaker but more consistent significant relationships with specific traits

35. WHAT DOES ACCURACY PREDICT?
FINDING 5:
WHAT DOES ACCURACY PREDICT?
Accuracy predicts:
Higher scores on Beliefs in Genetic Determinism (BGD) and Beliefs in Social Determinism (BSD) but no other measure of free will or determinism
genetic literacy scores (r = –.17, p < .01), years of education (r = –.12, p < .01), number of children (r = –.13, p < .01) and age (r = –.11, p < .01)
Gender: women are significantly more accurate t(1036) = –4.8, p < .01)).
Age is redundant to years of education and number of children: disappears in a multiple regression
Genetic literacy limited utility, not assessed in second (larger) sample

36. F(5, 732) = 7.21, p < .01

37. WHAT DOES ACCURACY PREDICT?
FINDING 5:
WHAT DOES ACCURACY PREDICT?
Accuracy predicts:
Higher scores on Beliefs in Genetic Determinism (BGD) and Beliefs in Social Determinism (BSD) but no other measure of free will or determinism
genetic literacy scores (r = –.17, p < .01), years of education (r = –.12, p < .01), number of children (r = –.13, p < .01) and age (r = –.11, p < .01)
Gender: women are significantly more accurate t(1036) = –4.8, p < .01)).
Only 5% of variance in accuracy predicted significantly.

38. SIBS STUDY IN PROGRESS! WHAT’S NEXT
So far (N = 115), no significant difference in estimates of genetic influence in these traits between adopted and biological offspring.
More responses + parent data = the first study of heritability of beliefs about heritability?

39. THANKS! Check out our preprint on OSF!
Many thanks to my coauthors and collaborators on this project:
Matt McGue
Alan Love
Jack Quigley
Bill Iacono
James Lee
Check out our preprint on OSF!
Other questions?