Interesting. Is it odd that the IQ scores were over 100?

For example, population IQ is supposed to be 100. So a score of 105 for boys with a 5 point drop would give us the expected result of average intelligence, right?

The wording in the summary could have been done better. Read casually, it comes across as suggesting causation instead of correlation:

Findings -- In this prospective birth cohort study, fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years.

Meaning -- Fluoride exposure during pregnancy may be associated with adverse effects on child intellectual development, indicating the possible need to reduce fluoride intake during pregnancy.

IQ scores? Really? Should we look at the correlation to phrenology reports and the subjects balance of humours as well?