Reality shows: Australian scientists made two groups, one watched reality shows and then made them take a test; the group that watched reality shows did way worse on the test.

Sugar: Los Angeles University proved that increased consumption of sugar slows down your brain.

Bubblegum: They say that bubblegum massages your brain, but University of Cardiff claims it messes with short-term memory.

Overeating: University of Kent checked out how good is the memory of overeating people that get a gastric bypass. Before the surgery it was below normal, and after the surgery it went up to normal.

Meetings: They should be a place to discuss ideas... In theory, because in reality people are afraid to speak their mind and take the "opinion of the group" as their own.

Corporal punishment: while many adults love being spanked, kids hate it. Corporal punishment can cause anxiety and even cause a child to be mentally challenged.

PowerPoint presentations: they should explain the problems but they're boring and usually information, say, for 5 slides in divided into 20 for better effect.

Secondhand smoking: University of Michigan claims that secondhand smoking is not only bad for your lungs but also lowers your IQ.

Pills: Ambien and Xanax for example used together are very bad for the nervous system.

Mary Jane: Duke University proclaimed that smoking Marijuana from an early age (when your body haven't fully developed) can suppress your growth and damage the brain.