You know how some people clam up and freeze and poop their pants and start crying when presented with a math problem (especially us ladies, amirite?)? Turns out, "math anxiety" is a totally legit thing, neurologically speaking—and a bit of a self-fulfilling prophecy as well.
Stanford University researchers scanned the child-brains of second- and third-grade students presented with addition and subtraction problems:
They discovered that those who feel panicky about doing math had increased activity in brain regions associated with fear, which caused decreased activity in parts of the brain involved in problem-solving.
"The same part of the brain that responds to fearful situations, such as seeing a spider or snake, also shows a heightened response in children with high math anxiety," said Vinod Menon, Ph.D.
So while it's possible for children with math anxiety to actually be good at math, they tend to do slower and sloppier work (understandable, since their brains are just screaming "SNAAAAAKE!!!" the entire time) and avoid advanced classes (because math class, to them, is basically a coffin full of spiders). Even worse, math anxiety seems to be self-perpetuating:
High math anxiety was accompanied by decreased activity in several brain regions associated with working memory and numerical reasoning. Interestingly, analysis of brain connections showed that, in children with high math anxiety, the increased activity in the fear center influenced a reduced function in numerical information-processing regions of the brain.
So your math anxiety shuts down your problem-solving capabilities, which makes you worse at math, which gives you math anxiety, which makes math harder, and so on. Fuck it. Let's go to the beach.