 Unconditioned reinforcers. These are reinforcers that you as an organism did not have to learn about. In other words, they are effective at increasing the probability of response. There's only a handful that are unconditioned. You could argue that all reinforcers are tied into these and I'll let you figure out how. It's food. That's drinking water. So anyway, food, water, sex, maybe warmth. Warmth is kind of the maybe one, possibly. Who knows? It could be. So there seems to be evidence that keeping warm is an unconditioned reinforcer. But sex is definitely an unconditioned reinforcement. So is water. And so is food. Basically, if the organism, if the species wants to stay alive, then these three things need to happen and they're important. They're the unconditioned reinforcers. Food, water, sex. That's all there's to it.