Beyond Little Albert

An article by carl Zimmer on fear in mice and men.

American psychologist John Watson decided to see if he could teach an 11-month-old baby named Albert to become scared of arbitrary things. He presented Albert with a rat, and every time the baby reached out to touch it, Watson hit a steel bar with a hammer, producing a horrendous clang. After several rounds with the rat and the bar, Watson then brought out the rat on its own. “The instant the rat was shown, the baby began to cry,” Watson wrote in a 1920 report. “Almost instantly he turned sharply to the left, fell over on his left side, raised himself on all fours and began to crawl away so rapidly that he was caught with difficulty before reaching the edge of the table.”

Oddly, just reading this description got my heart going faster

In the 1980s Caroline and Robert Blanchard, working together at the University of Hawaii, carried out a pioneering study on the natural history of fear. They put wild rats in cages and then brought cats gradually closer to them. At each stage, they carefully observed how the rats reacted. The Blanchards found that the rats responded to each kind of threat with a distinct set of behaviors.

The first kind of behavior is a reaction to a potential threat, in which a predator isn’t visible but there is good reason to worry that it might be nearby. A rat might walk into a meadow that looks free of predators, for example, but that reeks of fresh cat urine. In such a case, a rat will generally explore the meadow cautiously, assessing the risk of staying there. A second, more concrete type of threat arises if a rat spots a cat at the other side of the meadow. The rat will freeze and then make a choice about what to do next. It may slink away, or it may remain immobile in hopes that the cat will eventually wander away without noticing it. Finally, the most active threat: The cat glances over, notices something, and walks toward the rat to investigate. At this point, the rat will flee if it has an escape route. If the cat gets close, the rat will choose either to fight or to run for its life.

Turns out that fear in humans is very similar to fear in mice.

Fear, the new results suggest, is not a single thing after all. Rather, it is a complex, ever-changing strategy mammal brains deploy in order to cope with danger. When a predator is off in the distance, its prey—whether rat or human—powers up a forebrain network. The network primes the body, raising the heartbeat and preparing it for fast action. At the same time, the forebrain network sharpens the brain’s attention to the outside world, evaluating threats, monitoring subtle changes, and running through possible responses. Another important job it performs is keeping the midbrain network shut down so that, instead of fleeing at top speed, a prey animal keeps very still at first. As the predator gets closer, however, the forebrain’s grip on the midbrain loosens. Now the midbrain becomes active, orchestrating a powerful, quick response: fight or flight. At the same time it shuts down the slower, more deliberative forebrain. This is no time for thinking.