The Remarkable Power of Hope

Updated: Oct 28

by Joseph T. Hallinan, Psychology Today What The Research Says About Hope

Researchers in Denmark and the United States have shown that in the years immediately following their child’s death, mothers face a much higher risk of dying themselves. In 2012, Swedish researchers found that patients' risk of death from heart attack and stroke soared immediately after they received a diagnosis of cancer. And the likelihood of a heart attack or stroke increased with the severity of the cancer diagnosis—the darker the future looked, the greater the risk of cardiac death. This research, in many ways, builds on the work of late Johns Hopkins professor Curt Richter. In the 1950s, he conducted a gruesome experiment with domesticated and wild rats. He first took a dozen domesticated rats, put them into jars half-filled with water, and watched them drown. The idea was to measure the amount of time they swam before they gave up and went under. The first rat, Richter noted, swam around excitedly on the surface for a very short time, then dove to the bottom, where it began to swim around, nosing its way along the glass wall. It died two minutes later. Two more of the 12 domesticated rats died in much the same way. But, interestingly, the nine remaining rats did not succumb nearly so readily; they swam for days before they eventually gave up and died.

Now came the wild rats, renowned for their swimming ability. The ones Richter used had been recently trapped and were fierce and aggressive. One by one, he dropped them into the water. And one by one, they surprised him: Within minutes of entering the water, all 34 died. “What kills these rats?” he wondered. “Why do all of the fierce, aggressive, wild rats die promptly on immersion and only a small number of the similarly treated, tame, domesticated rats?”

The answer, in a word: hope.

“The situation of these rats scarcely seems one demanding fight or flight—it is rather one of hopelessness,” he wrote. “The rats are in a situation against which they have no defense … they seem literally to ‘give up.’” Richter then tweaked the experiment: He took other, similar rats and put them in the jar. Just before they were expected to die, however, he picked them up, held them a little while, and then put them back in the water. “In this way,” he wrote, “the rats quickly learn that the situation is not actually hopeless.” This small interlude made a huge difference. The rats that experienced a brief reprieve swam much longer and lasted much longer than the rats that were left alone. They also recovered almost immediately. When the rats learned that they were not doomed, that the situation was not lost, that there might be a helping hand at the ready—in short, when they had a reason to keep swimming—they did. They did not give up, and they did not go under. “After elimination of hopelessness,” wrote Richter, “the rats do not die.”

There are obviously many differences between humans and rats. But one similarity stands out: We all need a reason to keep swimming.

References Fang, F., et. al. (2012). Suicide and Cardiovascular Death after a Cancer Diagnosis. N Engl J Med., 366(14): 1310-7. Li, J., et. al., (2003). Mortality in parents after death of a child in Denmark: a nationwide follow-up study. Lancet, 361(9355):363–7. Li, J., et. al., (2002). Myocardial Infraction in Parents Who Lost a Child: A Nationwide Prospective Cohort Study in Denmark. Circulation, 106,1634-9.