My guess would be that we are too rushed, munching way too much information that scatter our brains, too prone to use shortcuts to get ahead (can't afford being deep), too busy to let ourselves sink into the very much needed meditative state, paradoxically too result-oriented to have time for quality, too fast-paced to let ourselves relax, get bored, and sleep enough. We are too reactive, too shallow, too busy, too stressed. We are constantly in an overexcited, coffee-pumped state following the patterns required to grind the results that meet the deadlines. And that's the opposite of a happy, alert, fresh, calm, sensitive state of being, in my opinion, that leads to good IQ results.