It is well established that both nature (genetics) and nurture(environment) play a role in who we are and how we behave ashumans. One way to examine the effect of nature vs. nurture is tostudy children who have been adopted at birth. These children areunique in that they received genes from their birth parents andhave environmental influence from their adoptive parents. Forexample, a research study can be conducted to see if the Body MassIndex (BMI) is more correlated with the BMI of his/her birth parentor adoptive parent. If the BMI of the child is more correlated withthe birth parent’s BMI, it means that the weight might begenetically determined to a larger extent compared to environmentalinfluence. If it’s more correlated with the adoptive parent’s BMI,then it means that the weight might be influenced by the behaviorof the adoptive parent to a larger extent.
Use the following dataset to answer the questions below:
| BMI |
Subject ID # | Child | Child’s Birth Parent | Child’s Adoptive Parent |
1 | 22 | 26 | 20 |
2 | 21 | 17 | 22 |
3 | 25 | 23 | 22 |
4 | 19 | 25 | 21 |
5 | 20 | 19 | 25 |
6 | 17 | 19 | 17 |
7 | 25 | 21 | 27 |
8 | 18 | 19 | 17 |
9 | 20 | 28 | 23 |
10 | 19 | 23 | 21 |
Questions:
- Calculate the mean and standard deviation for the adoptiveparents’ BMI. (2 points total: 1 for mean and 1 for SD- deduct .5if the process is correct but result is wrong)
- Calculate the Z scores for all the data points for the adoptiveparents. (1 point for calculating adoptive parents’ Z scores.Deduct .5 for each error in calculation)
- Calculate the Pearson’s correlation coefficient rbetween children’s BMI and their adoptive parents’ BMI. Note thatthe children’s Z scores have been calculated in Part 1 of thisscenario. (2 points total: 1 for work, 1 for r value)
- Explain the direction and strength of the relationship based onthe r. (2 points total: 1 for direction, 1 forstrength)
- What is the proportion of shared variance between children’sBMI and their adoptive parents’ BMI? That is, how much of thevariance in the children’s BMI can be predicted from their adoptiveparents’ BMI? (2 points total: 1 for work, 1 for result)
- Based on the two r statistics, what would be theanswer to the research question of whether children’s BMI isinfluenced more by nature or nurture? (1 point)
