[This is the first of a two-part series motivating and introducing precis, a Python package for automated abbreviation of psychometric measures. In part I, I motivate the search for shorter measures by arguing that internal consistency is highly overrated. In part II, I describe some software that makes it relatively easy to act on this newly-acquired disregard by gleefully sacrificing internal consistency at the altar of automated abbreviation. If you’re interested in this general topic but would prefer a slightly
less ridiculous more academic treatment, read this paper with Hedwig Eisenbarth and Scott Lilienfeld, or take a look at look at the demo IPython notebook.
Developing a new questionnaire measure is a tricky business. There are multiple objectives one needs to satisfy simultaneously. Two important ones are:
- The measure should be reliable. Validity is bounded by reliability; a highly unreliable measure cannot support valid inferences, and is largely useless as a research instrument.
- The measure should be as short as is practically possible. Time is money, and nobody wants to sit around filling out a 300-item measure if a 60-item version will do.
Unfortunately, these two objectives are in tension with one another to some degree. Continue reading
A recent paper has claimed that eating disorder symptoms, such as anorexia and bulimia are manifestations of an "extreme female brain". The evidence is actually confusing because some of the results apply more clearly to males than females. Gender stereotyped descriptions of "male" versus "female" brain types may be misleading.
Have you seen the lame pictures? Are the stresses of the presidency aging and weakening President Obama? Now that he is 50, what are his chances for a long life?
Does science add to what we know from philosophy and religion about the good life?
When choosing a career, finding the “perfect match” to your personality does not necessarily put you on a path toward thriving and long life. It was quite surprising to us what mattered more. The results were good news for career seekers.
Whether a person identifies with their head or their heart can say a lot about their personality. Are people in their heads really smarter than those in their hearts? The head/heart distinction might reveal something about how personality and intelligence are related. Shifting a person's attention between the head or the heart might change the way they think and behave.
Yesterday, as I was standing in line in my campus bookstore, I heard someone on the radio talk about a new study published in the Proceedings of the National Academy of Sciences (PNAS) showing that a computer algorithm, relying only on the things you “Like” on Facebook, makes more accurate judgments of your personality than your friends
. If you also heard about this study, you probably did not react the way I did yesterday. Having been a reviewer on this study, I had already read the paper. So my reaction was, “Yeah, the study did show that, but it isn’t as simple as this report makes it sound.”
So what does the study show? I personally was intrigued by three things.
1) Clearly there is a sexy news story in saying that computers make better judgments than humans. And that is precisely how
this study has been discussed so far
. However, the data show that self-other agreement with human judges was about r
= .49 (across all Big 5 traits) while self-other agreement with computer-based judgments was about r
= .56. Yes, these differences are statistically significant and NO we shouldn’t care that they are statistically significant. What these effectively mean is that if you judge yourself to be above average (median) on a trait, your friends are likely to guess that you are above average 74. Continue reading