After I read the Monitor's day-after-Thanksgiving editorial about what makes people happy, I thought about what my mother said at Thanksgiving dinner. My kids like each of us to relate things we are thankful for, and when it was my mother's turn, she said "Everything." We were surprised at her answer, but she insisted she was thankful for everything that she had.

In the past three months, my mother has declined significantly, both physically and mentally. She is 89 and has Parkinson's disease and dementia. She also has longstanding heart valve disease, which results in congestive heart failure, and a slow gastrointestinal bleed, which has led to anemia. She was seated at the Thanksgiving table in a wheelchair which she is unable to get into or out of without the assistance of one and sometimes two people. Except for eating, she can't do any activity - from using the bathroom to dressing to walking - without significant hands-on assistance. She had two recent hospitalizations and is living in a nursing home for rehabilitation. Many, many times that day, we reminded her that it was Thanksgiving.

My mother has progressed to a stage of dependence where some of us say, privately or out loud, that we wouldn't want to live like this. Our culture gives us objective phrases like "quality of life" to legitimize what are subjective beliefs. We are influenced by our youth and sports-obsessed society, to question how we could be happy if we lost our ability to move or to live independently. At one facility where my mother was admitted for rehabilitation after a broken hip, the nurse in charge tried to convince me of the poor reasoning in my mother's wish to be resuscitated if she stopped breathing, even though my mother would not otherwise die.

We may suppose that, because of her dementia, my mother doesn't realize how incapable she is, and therefore how unhappy she should be. It is true that my mother, like many persons with her stage of dementia, is unaware of the extent of her disability. According to an Alzheimer's disease website, the person cared for is less likely to be depressed than the family caregiver, a finding that raises issues about caring for the elderly, but settles any questions about the relationship of the extent of disability to happiness.

Indeed, in his intriguing book, Stumbling on Happiness, Harvard University psychologist David Gilbert reported that conjoined (Siamese) twins almost universally want to remain united. He offers and rejects several hypotheses for the twins' satisfaction with their life, which he

predicts most "singletons" would describe as depressing, maybe not worth living. Maybe the twins are happy because they simply don't know what they're missing. Like my mother, who forgets how disabled she is, maybe they don't realize how unhappy they should be. But, as Gilbert points out, not knowing what you're missing may be precisely the reason you are happy, and doesn't invalidate your subjective experience of happiness.

He also hypothesizes that the twins may use language differently; they say they're feeling ecstatic when the rest of us would say we are feeling okay. But he points out that it is impossible to prove this, because happiness is always subjective, and seen from one's particular point of view.

Gilbert cites research that non-disabled people tend to underestimate the happiness of people with chronic illnesses or disabilities. According to that study, healthy people who are asked to imagine themselves in a particular state of poor health give their lives less value than do people with disabilities who are actually in such a state. He also cites research that non-disabled people are willing to pay more to avoid disability than disabled people are willing to pay to become able-bodied again. The explanation, again, is that non-disabled people underestimate the happiness of those who have disabilities.

I suppose that the opposite is also true - that people tend to overestimate the unhappiness of people with disabilities. Join our misconceptions about disability to our conceptions about happiness, and the two don't link up. In reality, I needn't doubt that my mother really is thankful for everything.

I should know better, because being legally blind all my life has not in itself made me unhappy. I think some people don't really believe this. I can't remember anyone ever saying this outright. However, like other people with disabilities, I sometimes got compliments about traits like perseverance I supposedly have, or am complimented just because I am a mother and lawyer.

My sister-in-law, who has a doctorate in biochemistry, as well as three children, and is physically disabled from polio, has been admired for her "courage." These comments are well-meant, but the subtle message is that we shouldn't have done these things, and to do them, we must have more strength or determination than a non-disabled person. That's certainly not true for me! We have "overcome" our disability, which would otherwise have led to less of a life than a normal person could expect.

According to that post-Thanksgiving editorial, happy people watch less TV. This holiday season, some of us nonetheless will risk our well-being to view, once again, It's a Wonderful Life. Frank Capra may have intended bitter Mr. Potter's wheelchair to serve as a metaphor for his crippled personality. Let's remember that this metaphor is distorted by society's lens.

(Sheila Zakre of Concord has been a lawyer for 21 years and owns the Zakre Law Office, which specializes in elder and disability law.)