Impulsive, inattentive, does not sit still, does not play well with others, and throws a lot of temper tantrums are all symptoms that my step-bother has had for years. They are also common symptoms of attention-deficit/hyperactive disorder. Children with this disorder are diagnosed with or without hyperactivity. My step-brother definitely has the hyperactivity part of the disorder.
I will remember this concept from psychology because I never really knew what it meant to have ADHD until I came across the definition of it the text book. My step-brother takes medication for the disorder, and the disorder has also gotten better with age, just as the text book says it might do. My step-brother still has trouble in school and in learning and still has bad balance and coordination. He also lacks commonsense. Other than those issues, most of his symptoms simmer down when he takes his medication on a daily basis.
My step-brother's first boy cousin, too, has ADHD. Studies have shown heritability is as high as .80. The boys' grandpa also has symptoms of the disorder and had a lot of troubles growing up. Because I can associate the concept with my life, I will remember the symptoms of attention-deficit/hyperactive disorder and the statistics about it for many years to come.