My professors were an amusing bunch

A collection of excellent or humorous things my professors have said this semester:

General chemistry: To illustrate chemical concepts, my professor liked to give examples about both prescription and recreational drugs. This would have been amusing all on its own, but her deadpan humor and the fact that she is short and middle-aged just added an extra layer of unexpected excellence.
In one example, she used heroin as an example of… I don’t remember precisely, but it had something to do with enthalpy.
At any rate, she said this: “It’s a real problem, drug dealers putting [some dangerous substance] in heroin, here in New York. I’ve given it up completely.”

Neuroscience: We had a rotating cast of professors for this class; one would come in, do a series of lectures on a subject, and then hand off the stick to someone else. The first lecturer was all right. He insisted on drawing his lectures, despite his inability to operate a pen in a manner such that the result was elucidating and comprehensible, and was a bit of a wise guy. However, in our discussion of the importance of correct potassium and sodium concentrations in, y’know, having neurons work right, he mentioned how potassium chloride, which dissociates to form potassium ions in solution, could severely upset the chemical equilibria and cause convulsions. What was excellent, though, was that he followed it up with: “This is what we use to kill each other.” Referring to lethal injections, of course. (Professors who realize that science is not divorced from ethics and actually expound on it to a degree are some of my favorites.)

Another one from neuro: Later in the semester, we had a lecture on neurological disorders, namely schizophrenia and depression. Before delving into it, our professor prefaced his lecture with a statement on how you should never bully, harass, or laugh at people with debilitating mental diseases, for the same reason you wouldn’t laugh at someone who was born without legs. It’s not their fault and you should be kind, not cruel. With the stigma that does surround mental illness in our culture, I thought this was a wonderful preface.

Genetics: The semester’s lectures were concluded with a lecture on the genetic basis of behavior, and whether or not behavior can be predicted as arising from purely genetic phenomena. Our professor made some asides during this, all of them poignant. The first was that, though there is genetic variation across human populations, 85 to 90% of it is non-geographically distributed. Which is to say, more or less, that the overwhelming majority of genetic variance in humans is unrelated to race or ethnicity. Additionally, in studies between identical twins, only about 0.5 of behavioral variation is heritable.

Toward the end of the lecture, during which he had discussed the genetic basis of behavior and various quantitative ways it has been examined, he took a moment to mention how it is dangerous to assume that behavior can be easily described by genetics (for those of you who have taken high school biology – it is not remotely Mendelian). As an example, he brought up eugenics in the early 20th century, and how the idea that genetics predicts behavior was used to justify horrific acts, such as the forced sterilization of the mentally disabled or other “societally unwanted” people.

The kicker was this: When we discussed how the reason for the inability of genetics to predict behavior was that there were simply too many interacting genes, the professor made an aside to say that he was glad that there were many genes that affected behavior, because it’ll be much harder to use them to underscore arguments about who should be putting whom in jail.