Model!

May 20th, 2012| Topic: RaMbLeS | 2

It is always hard to model and study social interactions and the effects these interactions have on our behavior. But one researcher with the National Bureau of Economic Research, Cambridge, MA, attempted to do just that. Bruce Sacerdote studied peer effects in a setting where peers are randomly assigned: entering freshmen in Dartmouth College are randomly assigned dorms and roommates. In one smooth stroke, Sacerdote eliminated the self-selection bias by which roommates normally select one another based on certain known characteristics—city of origin, major of study, interests in leisure, etc.

He found, perhaps not surprisingly, that level of academic effort was significantly dependent on peer effects and interactions. In other words, one studied harder and did better in courses, if one associated with peers with good study habits. And Sacerdote discovered that roommate’s behavior (academic effort and studiousness) played a greater role in this than the roommate’s background, parental income and education, student high school GPA, fraternity membership, and whether or not the student reported drinking beer in the past year, etc.

And he crunches all the data (it gets too mathematical for me):

For two roommates i and j,
(1)  GPA_i = d + a* ACA_i + b* ACA_j + γ*GPAj + ε_i
(2)  GPA_j = d + a* ACA_j + b* ACA_i + γ*GPAi + ε_j
where e_i and e_j ~ N(0, σ_e²) .

Etc. (And it only gets worse.)

But here’s the bottom line:

I find that roommate peer effects are important influences in freshman year GPA ….”

[Parents, take note!]

In other words, for some things at least (here, freshman year GPA), you become like the ones with whom you associate.

The Book of Proverbs agrees:

He who walks with wise men will be wise ….
Proverbs 13:20

But Proverbs also warns one that the corollary is also possible: for some things at least, there is the danger of becoming like the evil ones with whom I may associate.

… but the companion of fools will suffer harm.
Proverbs 13:20

Intoxication and gluttony and anger are also, apparently contagious!

Do not be with heavy drinkers of wine,
Or with gluttonous eaters of meat;
For the heavy drinker and the glutton will come to poverty,
And drowsiness will clothe one with rags.
Proverbs 23:20–21

Do not associate with a man given to anger;
Or go with a hot-tempered man,
Or you will learn his ways
And find a snare for yourself.
Proverbs 22:24–25

Later, Paul cites a third-century BC Greek dramatist, Menander, to make the same point.

Do not be deceived: “Bad company corrupts good morals.”
1 Corinthians 15:33

On the other hand, in the Bible, children of God are commanded to be good influences, as models and examples of Christlikeness.

Do all things without grumbling or disputing;
… children of God above reproach
in the midst of a crooked and perverse generation,
among whom you appear as lights in the world.
Philippians 2:14–15

Let no one look down on your youthfulness,
but rather in speech, conduct, love, faith and purity,
show yourself an example of those who believe.
1 Timothy 4:12

In all things show yourself to be an example of good deeds,
with purity in doctrine, dignified,
sound in speech which is beyond reproach.
Titus 2:7–8

After all, that’s what Christians are called for.

But you are a chosen race, a royal priesthood,
a holy nation, a people for God’s own possession,
so that you may proclaim the excellencies of Him
who has called you out of darkness into His marvelous light.
1 Peter 2:9

Lights in a dark world. Modeling Christlikeness!