8 SCIENTIFIC AMERICAN MIND July/August 2013

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Life Satisfaction Linked to Personality Changes Character trumps economic concerns to in� uence our happiness

Despite the long-held belief that personality traits are set in stone, numerous studies have

found evidence to the contrary (time-line below). Now research reveals that a changing character can in� uence life satisfaction even more than economic upheaval.

Past studies have revealed that per-sonality is the single biggest factor in how we perceive our own well-being, ac counting for 35 percent of individual differences in life satisfaction. Research on well-being, however, has focused on less important factors, such as income and job status, because of the misper-ception that personality is generally � xed after early adulthood.

The new study, published in March

in Social Indicators Research, investi-gated how evolving character traits re-late to life satisfaction. Researchers at the University of Manchester in Eng-land assessed 8,625 people aged 15 to 93 at two points, four years apart. They measured the Big Five personality traits (openness to experience, conscientious-ness, extroversion, agreeable ness and neu roticism) and tracked � uctuations in external aspects of subjects’ lives, in-cluding marital status, income and em-ployment status.

The data reveal that the participants’ character changed during those four years at least as much as demographic factors, such as marital status or employ-ment. And those small personality shifts were more closely tied to life satisfaction than the other indicators were. For in-stance, people who grew less agreea ble reported feeling less ful� lled in life than they had felt four years earlier, whereas those who became more open reported greater contentment.

This study did not attempt to � nd out

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Creativity is often overlooked in schools. Only nine U.S. states include creativity as a criterion for gifted education. l Rats who were tickled once a day for two weeks later responded less to stress. l In a major advance, scientists created a see-through brain by replacing its lipids with a hydrogel. M

>> Temperament How we grow over time

Our Peripatetic PersonalityDecades of studies slowly overturn the belief that our character is stable.

eFlexible Facets Some personality traits may be more malleable than others. A study from theeMarch International Journal of Geriatric Psychiatry found that 75-year-olds in the 1970s were less eextroverted than 75-year-olds in the 2000s, though equally neurotic. The � ndings suggest thateextroversion may be more susceptible to environmental in� uences than neuroticism is. —T.R.

1976 1988 1997 2003Research con-� rms the widely held idea that a person’s person-

ality remains stable from early

adulthood to old age.

Self-reports from men and women aged 21

to 96 and ratings from spouses sug-gest that adult per-

sonality is static after about age 30.

A study suggests person-ality may still be malleable in adulthood. Women aged

27 to 43 exhibited in-creases in industrious-

ness, assertiveness and con� dence after experi-encing success at work.

Further evidence emerges that personality changes over time. Adults aged

21 to 60 reported increases in conscientiousness

and agreeableness with age and, in women,

decreases in neuroticism.

ILLUSTRATIONS BY NOMA BAR

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Mind.Sc ient i f icAmerican.com SCIENTIFIC AMERICAN MIND 9

Creativity is often overlooked in schools. Only nine U.S. states include creativity as a criterion for gifted education. l Rats who were tickled once a day for two weeks later responded less to stress. l In a major advance, scientists created a see-through brain by replacing its lipids with a hydrogel.

ON THE HORIZON

Nanotechnology That Detects and Treats Alzheimer’s

A quick sniff of a nasal spray sends microscopic metal particles into the brain, where they target and destroy the damaging proteins of Alzheimer’s disease. No Alzheimer’s? No prob-lem—the metal particles pass out of the body safely. Such is the promise of technology being developed by neuro-scientist William Klein and nanotech-nologist Vinayak Dravid of Northwest-ern University. The pair has invented a nanotech-based early-detection system that might one day deliver targeted treatments.

Klein and Dravid created an antibody—an immune molecule that detects speci� c chemical struc-tures—that binds to a particle impli-cated in Alzheimer’s. They linked the antibody to a nanoscale arrangement of iron oxide compounds, similar to rust, which can be seen with magnetic resonance imaging. The brain scan could detect the disease early on, so patients can start treatment sooner than they can today. “Once the chain reaction of negative events starts, it’s like a lit fuse. You want to intervene as soon as possible,” Klein says.

Globs of beta-amyloid protein called plaques are a hallmark of Alzheimer’s. But these days most neuroscientists agree that a tiny particle form of the same protein, called an oligomer, is the primary toxin in the illness. Eventually these smaller structures glom together to form plaques, but by then they have already damaged brain cells. The antibody created at Northwestern binds to the toxic oligomers and could one day deliver therapies to the brain or help clinicians evaluate how a patient is responding to a new medication.

So far the researchers have used the probe to distinguish between diseased and healthy human brain samples. The next step, slated for later this year, is to see if they can do the same in the brains of living mice. Already a nasal spray has successful-ly delivered the nanoparticles to a mouse’s brain, most likely the same delivery method that would work for us humans. —Stephani Sutherland

Forces of Personality Change

Greater job satisfaction Decreases

neuroticism and in-creases extroversion

DivorceIncreases extroversion

and openness in women

Stronger relationships Increase conscientious-ness, agreeableness

and extroversion and decrease neuroticism

Remarriage Decreases

neuroticism in men

Taking antidepressants Increases extroversion and decreases neuroti-

cism in depressed individuals; effects on

personality were separate from those

on depression

Intensive drug counseling

Enhances agreeable-ness and conscien-tiousness in addicts

separate from those on depression

Stronger relationshipsIncrease conscientious-ness, agreeableness

Taking antidepressantsIncreases extroversion and decreases neuroti-

cism in depressed individuals; effects on

separate from those separate from those

neuroticism in men Enhances agreeable-ness and conscien-tiousness in addictstiousness in addicts

neuroticism and in-creases extroversion

Increases extroversion

Stronger relationshipsIncrease conscientious-ness, agreeableness

neuroticism in men

2006 2011 2013A meta-analysis � nds that throughout adulthood, people

become more open, extro-verted, conscientious and

emotionally stable, but some of these traits—openness and extroversion—start to

decline in old age.

A study reveals that shifts in personality over time predict well-being and life satisfaction:

increases in agreeable-ness and extroversion,

for example, are linked to greater life satisfaction.

New work indicates personality changes may follow a bell-curve

trajectory, with emotional stability, extroversion, openness and

agreeableness increasing until midlife (aged 40 to 60) and de-

creasing after that; conscientious-ness, however, rises with age.

what caused the subjects’ personalities to transform, but other recent work has shown that certain experiences can change speci� c traits. For instance, psy-chological trauma—such as that experi-enced by combat soldiers—has been linked with decreases in agreeableness and conscientiousness (for more exam-ples, see below).

Scientists have also successfully de-signed programs to increase openness, which tends to predict better health and a longer life. A December 2012 ex-periment published in Psychology and

Aging found that a training program increased openness among older adults. A different study found that openness grew with the enhanced bodily aware-ness that comes from dancing and pos-sibly other forms of physical activity.

“Not only does personality change occur, but it is an important in� uence and a possible route to greater well-be-ing,” says research psychologist Chris-topher Boyce, now at the University of Stirling in Scotland, lead author of theSocial Indicators Research study.

—Tori Rodriguez

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