If artistic ability has a strong influence on intelligence compared to athleticism, then P(intelligent | artistic) >= P(intelligent | athletic). We know that P(athletic) > P(artistic) from the data.
By Bayes' theorem:
P(intelligent | artistic) = P(artistic | intelligent) * P(intelligent) / P(artistic).
P(intelligent | athletic) = P(athletic | intelligent) * P(intelligent) / P(athletic).
Ignoring P(intelligent) for a sec, we find
P(intelligent | artistic) ~ P(artistic | intelligent) / P(artistic)
P(intelligent | athletic) ~ P(athletic | intelligent) / P(athletic)
If we accept the assumption that artistic ability is a bigger influence, then
P(artistic | intelligent) / P(artistic) > P(athletic | intelligent) / P(athletic)
Because P(athletic) > P(artistic),
P(artistic | intelligent) > P(artistic) * P(athletic | intelligent) / P(athletic)
P(artistic)/P(athletic) must be less than 1, so we get
P(artistic | intelligent) > P(athletic | intelligent)
I'm not really sure where I was headed with this, but it was neat to think about. If anyone spots an error please just correct me.