“This summer my 93-year-old mother-in-law died, a few months after her 94–year-old husband. For the last five years she had suffered from Alzheimer’s disease. By the end she had forgotten almost everything, even her children’s names, and had lost much of what defined her—her lively intelligence, her passion for literature and history. Still, what remained was her goodness, a characteristic warmth and sweetness that seemed to shine even more brightly as she grew older. Alzheimer’s can make you feel that you’ve lost the person you loved, even though they’re still alive. But for her children, that continued sweetness meant that, even though her memory and intellect had gone, she was still Edith. A new paper in Psychological Science reports an interesting collaboration between the psychologist Nina Strohminger at Yale University and the philosopher Shaun Nichols at the University of Arizona. Their research suggests that Edith was an example of a more general and rather surprising principle: Our identity comes more from our moral character than from our memory or intellect. Neurodegenerative diseases like Alzheimer’s make especially vivid a profound question about human nature. In the tangle of neural connections that make up my brain, where am I? Where was Edith? When those connections begin to unravel, what happens to the person? Many philosophers have argued that our identity is rooted in our continuous memories or in our accumulated knowledge. Drs. Strohminger and Nichols argue instead that we identify people by their moral characteristics, their gentleness or kindness or courage—if those continue, so does the person. To test this idea the researchers compared different kinds of neurodegenerative diseases in a 248-participant study. They compared Alzheimer’s patients to patients who suffer from fronto-temporal dementia, or FTD. More From Alison Gopnik Aggression in Children Makes Sense—Sometimes Cooking Has a Place in Human Evolution Smarter Every Year? Mystery of the Rising IQs Brains, Schools and a Vicious Cycle of Poverty The Mystery of Loyalty, in Life and on ‘The Americans’ How 1-Year-Olds Figure Out the World . FTD is the second most common type of dementia after Alzheimer’s, though it affects far fewer people and usually targets a younger age group. Rather than attacking the memory areas of the brain, it damages the frontal control areas. These areas are involved in impulse control and empathy—abilities that play a particularly important role in our moral lives. As a result, patients may change morally even though they retain memory and intellect. They can become indifferent to other people or be unable to control the impulse to be rude. They may even begin to lie or steal. Finally, the researchers compared both groups to patients with amyotrophic lateral sclerosis, or ALS, who gradually lose motor control but not other capacities. (Physicist Stephen Hawking suffers from ALS.) The researchers asked spouses or children caring for people with these diseases to fill out a questionnaire about how the patients had changed, including changes in memory, cognition and moral behavior. They also asked questions like, “How much do you sense that the patient is still the same person underneath?” or, “Do you feel like you still know who the patient is?” The researchers found that the people who cared for the FTD patients were much more likely to feel that they had become different people than the caregivers of the Alzheimer’s patients. The ALS caregivers were least likely to feel that the patient had become a different person. What’s more, a sophisticated statistical analysis showed that this was the effect of changes in the patient’s moral behavior in particular. Across all three groups, changes in moral behavior predicted changes in perceived identity, while changes in memory or intellect did not. These results suggest something profound. Our moral character, after all, is what links us to other people. It’s the part of us that goes beyond our own tangle of neurons to touch the brains and lives of others. Because that moral character is central to who we are, there is a sense in which Edith literally, and not just metaphorically, lives on in the people who loved her. ”
