You probably could've figured this one out by watching five minutes of The X-Factor, right? The worrying thing here, is that I'm only half joking. We know that our brains are actually getting smaller, over the past 20,000 years (a mere blink in evolutionary time) the average brain size has reduced by about the size of a tennis ball, but scientists are still unsure as to why that is...and whether we really are getting dumber. There are a couple of theories, one of which is that a smaller brain is actually more efficient. This makes our brains quicker and more agile as the brain signals literally don't have to travel as far. Let's hope this is the reason. There are some that think that the smaller brain size is actually a result of humans effectively domesticating themselves. Domesticated dogs, cats, pigs, sheep, cattle etc. all have smaller brains than their wild ancestral counterparts. Worryingly, another hypothesis (or rather, collection of hypotheses), do seem to indicate that we are actually getting dumber. There's one suggestion that the invention of agriculture played a role as, at its inception, human diets became deficient in protein, possibly affecting brain size. Alternatively, some think that the large, densely populated groups that we live in now mean that the division of labour is greater, meaning that we just don't have to think or innovate as much and we are genuinely getting dumber. Until they prove it once and for all, it's up to you which of these you want to believe.
