Kettle Thought of the day: Sexy Heads
Drink: Lemon and Ginger Tea
There is a fundamental discrepancy in the way hard work is rewarded in terms of attractiveness. When someone works out, plays sport, inhales protein powders, and pumps metaphorical iron, they are compensated with a muscular well-proportioned physique; one that the opposite sex finds extremely attractive. However, if you work out your brain, read books, write papers, and pump mental iron(y), your compensation, although a fantastic asset, is completely invisible to the naïve observer. Not only that; you will probably also forego much physical activity and thus end up less muscular than ordinary. This is not attractive.
The problem is that, in the modern age, a superior mental capacity has replaced a superior physical capacity for the provision of resources. To throw a little evolutionary theory into the mix; a big strong-looking male used to indicate his ability to hunt, protect and provide. Nowadays it signifies that he spends too much time with his sweaty friends in the gym, homoerotically watching each other do reps on all manner of ridiculous machines. Superior ability to provide and protect is now determined by mental capacity and entrepreneurship (professional athletes aside; who make up a very small percentage of the population anyway). So why then do women still find blokes who look like deformed rugby players attractive?
The most logical explanation is that society has shifted towards the success of the brainy only very recently in our evolutionary history, and that there is a lag whilst our evolved tendencies play catch-up. Therefore, I can see the powers of sexual selection providing one of two possible outcomes (or maybe both):
- Women will start finding men who look nerdy much more attractive than big muscular behemoths (who will probably suffer from weight-related health problems and back pain in later life anyway), or…
- Humans will start exhibiting observable physical indicators of intelligence. Perhaps for every item of information we learn, our head will increase in size. Only a microscopic, unnoticeable amount, but as you continue to learn and learn it will start to look visibly intelligent. You will have to make way on the street for people with doctorates as they struggle to navigate their massive heads through the crowd, pursued by a flock of aroused women.
I am almost entirely positive that this will happen. Maybe… 90% certain that, one day, ladies will find fellas with massive heads completely irresistible. And if you can manage to find the time to get yourself a set of muscles to go with that big head (just to cover your bases), you can think of yourself as the ‘evolved Brad Pitt’.

The undeniable future of 'sexy'...perhaps
Your second idea is fatally flawed in that knowledge cums in all sorts of forms. For example if a football hooligan can tell you the score of every Millwall game this season their head would grow due to this seemingly useless knowledge, however someone who knows a shit load about something useful would have the same sized head. Therefore i believe that option 1 is the more likely. Also why is it the head is what has to grow we could evolve so that the more we learn the bigger our muscles get. But all of this is negated by the fact bitches love big willies more than big muscles
If neurons were situated in biceps then perhaps a healthy appetite for knowledge would be athletically beneficial. And I suppose my logic would lead to taxi drivers with their massive hippocampi being the sexiest men on earth. And then all of it will, if your predictions are correct, be negated by the first straight bloke that plucks up the courage to wear crotchless jeans on a night out.