Results of yesterday's personality poll: we're strange.
On the hypothesis that this site selects for certain personality types that are different from the general population, I decided to run some simple statistics on the results of yesterday's MBTI poll (http://news.ycombinator.com/item?id=943722).

I compared the frequencies of each of the types to the population means on the Wikipedia article (http://en.wikipedia.org/wiki/Myers-Briggs_Type_Indicator#Type_dynamics_and_development). The results show that we are a very atypical group indeed:

Using a binomial test at a 99% confidence level.
ISTJ is significant: 1.82% ( 12/660) vs. 11.60% expected.
ISFJ is significant: 0.61% ( 4/660) vs. 13.80% expected.
INFJ is NOT significant: 2.12% ( 14/660) vs. 1.50% expected.
INTJ is significant: 31.21% (206/660) vs. 2.10% expected.
ISTP is significant: 2.42% ( 16/660) vs. 5.40% expected.
ISFP is significant: 0.15% ( 1/660) vs. 8.80% expected.
INFP is significant: 8.48% ( 56/660) vs. 4.30% expected.
INTP is significant: 28.94% (191/660) vs. 4.30% expected.
ESTP is significant: 0.45% ( 3/660) vs. 4.30% expected.
ESFP is significant: 0.15% ( 1/660) vs. 8.50% expected.
ENFP is significant: 3.33% ( 22/660) vs. 8.10% expected.
ENTP is significant: 8.48% ( 56/660) vs. 3.30% expected.
ESTJ is significant: 1.36% ( 9/660) vs. 8.70% expected.
ESFJ is significant: 0.76% ( 5/660) vs. 12.30% expected.
ENFJ is NOT significant: 2.27% ( 15/660) vs. 2.40% expected.
ENTJ is significant: 7.42% ( 49/660) vs. 1.80% expected.

The data are up-to-date as of about 20 minutes ago. Here's the script I used to generate these results: http://gist.github.com/236850

EDIT:

Here are the results broken down by pairs:

FP is significant: 12.12% ( 80/660) vs. 29.70% expected.
TP is significant: 40.30% (266/660) vs. 17.30% expected.
FJ is significant: 5.76% ( 38/660) vs. 30.00% expected.
NJ is significant: 43.03% (284/660) vs. 7.80% expected.
NF is NOT significant: 16.21% (107/660) vs. 16.30% expected.
TJ is significant: 41.82% (276/660) vs. 24.20% expected.
NP is significant: 49.24% (325/660) vs. 20.00% expected.
NT is significant: 76.06% (502/660) vs. 11.50% expected.
EN is significant: 21.52% (142/660) vs. 15.60% expected.
EJ is significant: 11.82% ( 78/660) vs. 25.20% expected.
IP is significant: 40.00% (264/660) vs. 22.80% expected.
IS is significant: 5.00% ( 33/660) vs. 39.60% expected.
EF is significant: 6.52% ( 43/660) vs. 31.30% expected.
IT is significant: 64.39% (425/660) vs. 23.40% expected.
IJ is significant: 35.76% (236/660) vs. 29.00% expected.
IN is significant: 70.76% (467/660) vs. 12.20% expected.
ET is NOT significant: 17.73% (117/660) vs. 18.10% expected.
EP is significant: 12.42% ( 82/660) vs. 24.20% expected.
ES is significant: 2.73% ( 18/660) vs. 33.80% expected.
IF is significant: 11.36% ( 75/660) vs. 28.40% expected.
SP is significant: 3.18% ( 21/660) vs. 27.00% expected.
ST is significant: 6.06% ( 40/660) vs. 30.00% expected.
SJ is significant: 4.55% ( 30/660) vs. 46.40% expected.
SF is significant: 1.67% ( 11/660) vs. 43.40% expected.

Apparently, 76% of Hacker News is an NT type of one type or another. I've updated the Gist link above with the code that computes this.