Deck 1: Genetics: Twin Investment Behavior; Investments of Adoptees and the Human Genome

Question 1

What are the fundamental questions and issues in the nature versus nature debate?

Answer 1

The fundamental question is how much of human behaviour is learned from nurture, such as upbringing and personal experiences, versus the genetics of nature. The answer could have significant policy ramifications.

Question 2

Why do genetics studies compare identical twins behavior to fraternal twins behavior?

Answer 2

Identical twins come from one egg and one sperm resulting in them sharing 100% of their DNA. Alternatively, fraternal twins come from two eggs and two sperm, which means that they share roughly 50% of their DNA. Therefore, if we assume that twins who are raised together will share the same upbringing (i.e.) nurturing experience, we can deduct that if identical twins have more similar decisions to fraternal twins, DNA must explain the difference. Furthermore, this relationship should be stronger for fraternal twins of the same sex, as they were more likely to have more shared childhood experiences as it is possible that opposite sex fraternal twins may participate in different activities due to gender social norms such as boys participating more in sports and girls playing with dolls.

Question 3

What can we conclude from twin studies about risk taking?

Answer 3

Compared to fraternal twins, identical twins are more likely to have similar:
Savings behaviour
Homeownership rates
Risk preferences in gambles
Stock market participation rates
Pension choices
Investing styles
Therefore, some aspect of this investment behavior must be driven by genetics.

Question 4

What does twin research say about the source of irrational behaviour such as investment biases?

Question 5

How does adoption research examine the influence of genetics on behavior?

Question 6

How does adoption research explain the impact of genetics in financial decision making?

Question 7

What is the biggest issue with research using DNA data and how do they work around this issue?

Question 8

What does research using the human genome say about investors financial decisions?