Neither, as a race we are so varied that there are idiots and geniuses in both genders. Also, for example, some people may be academic geniuses but are completely dead in the water when it comes to real world intelligence skills (common sense, social interactions, rational thought, etc). Others may excel in these areas, but lack academic skills.
'Intelligence' covers too huge a scope and humans far too varied for an answer beyond
neither.
I would say that intelligence as a whole is getting worse though.
you may get better answers if you asked "how long is a piece of string?" though xD
Twice the length from the middle to the end