We’ve all seen them – headlines about scientific findings that cause people to roll their eyes and say “but that’s obvious – I can’t believe my tax dollars were wasted on doing a study on that”. You know the sort of thing I’m talking about “Study shows that abused children are less trusting”, “Study shows Jews are less likely to vote for anti-semitic candidates”, “Study shows that students addicted to heroine do worse in school”. I made those particular headlines up, but those sorts of headlines, and the “well, duh” response that they provoke are all too common .
One of the problems with many studies in social science is that oftentimes no matter what a study finds it will feel obvious, even though you couldn’t have predicted the outcome a priori. Hindsight is 20/20, as they say. Take for example the following pairs of theories of human behavior that could be tested:
Opposites attract vs. Birds of a feather flock together
What’s good for the goose is good for the gander vs. Men are from Mars, women are from Venus
Absence makes the heart grow fonder vs. Out of sight, out of mind
Too many cooks spoil the broth vs. May hands make light the work
He who hesitates is lost vs. Look before you leap
Smiling faces tell lies vs. A smile means friendship to everyone
No matter which of them turns out to be true, there is a famous aphorism (or song lyric, or book title, etc.) that goes along with it. And so no matter what you find, people will say “I knew that – my grandfather always said that”. But the problem is that grandpa also said the opposite, and unless you do the study, you can’t know which of them was right. We often have conflicting intuitions, and what’s ‘obvious’ in hindsight may actually not have been predictable in advance.
There’s also the problem of different people having different, but (very strong) opinions about human nature. In the current partisan climate of American politics, both the Democrats and the Republicans make strong assumptions about what drives human behavior. And those assumptions often directly conflict. On certain issues, no matter what a study finds, about half of America will think that the results were obvious. (The other half will dismiss the results as obviously flawed and biased, but that’s a topic for another post). But a priori, you don’t know which half will fall which way – again things that seem obvious are often actually surprisingly controversial.
Finally, what is “obvious” isn’t always true. For most of human history it was “obvious” that the world was flat and that the sun revolved around the earth. People have strong intuitions about human behavior and the natural world – those intuitions are often wrong. Unless you test them, you can’t know.