Toxoplasmosis again

I'd asked before how toxoplasma could change hormone levels from within a cyst. There's a new report in the European Journal of Personality that says yep, they do.

We found that Toxoplasma-infected male and female students had significantly higher extraversion and lower conscientiousness. The conscientiousness negatively correlated with the length of infection in men, which suggested that the toxoplasmosis associated differences were more probably the result of slow cumulative changes induced by latent toxoplasmosis, rather than transient side effect of acute Toxoplasma infection. The existence of this correlation also supported (but of course not proved) the hypothesis that Toxoplasma infection influenced the personality, rather than the hypothesis that the personality influenced the probability of the infection.

...

The final sample consisted of 181 Toxoplasma-negative and
30 Toxoplasma-positive female students and 95 Toxoplasma-
negative and 17 Toxoplasma-positive male students.

...

The important difference between the present NEO-PI-R personality profile and 16PF personality profiles of infected subjects was that the toxoplasmosis-associated differences relative to Toxoplasma-free subjects in Cattell's personality factors were mostly in opposite directions for men and women, whereas the differences in NEO-PI-R factors were generally in the same direction for both genders.

I must say I'm not excited about their Table 1. Yep, there are differences, but the standard deviations are pretty large.

But I had a look at some pictures and maybe the cysts aren't quite as impermeable as I'd have guessed. So they may be onto something, though unless I miss my guess this study doesn't show it. There just aren't enough statistics to look at the tails properly.