racism and homophobia are linked to having lower IQ as those with lower intelligence tend to gravitate toward socially conservative ideologies.
IQ averages have bee declining over recent decades due to the fact that smarter people are having less children.
IQ is the number that predicts the extent to which one will perform successfully on subsequent IQ tests.
First born children have higher IQ's than their younger siblings.

Men who are unfaithful tend to have lower IQs.
IQ can decrease by an average of 13% when people are more stressed
Iodine was added to salt in 1924 to combat goiters, but the iodization also resulted in notable increases in intelligence
Poor eyesight (myopia) is associated with higher IQ.
IQ is a silly metric. It turns out that there is an unusually high and consistent correlation between the stupidity of a given person and that person's propensity to be impressed by the measurement of I.Q.