Posts Tagged ‘personality’

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How and why human-unique characteristics such as highly social behavior, languages and complex culture have evolved is a long-standing question. A research team led by Tohoku University in Japan has revealed the evolution of a gene related to such human-unique psychiatric traits.

PhD candidate Daiki Sato and Professor Masakado Kawata have discovered SLC18A1 (VMAT1), which encodes vesicular monoamine transporter 1, as one of the genes evolved through natural selection in the human lineage. VMAT1 is mainly involved in the transport of neurochemicals, such as serotonin and dopamine in the body, and its malfunction leads to various psychiatric disorders. VMAT1 has variants consisting of two different amino acids, threonine (136Thr) and isoleucine (136Ile), at site 136.

Several studies have shown that these variants are associated with psychiatric disorders, including schizophrenia, bipolar disorder, anxiety, and neuroticism (a personality trait). It has been known that individuals with 136Thr tend to be more anxious and more depressed and have higher neuroticism scores. They showed that other mammals have 136Asn at this site but 136Thr had been favored over 136Asn during human evolution. Moreover, the 136Ile variant had originated nearly at the Out-of-Africa migration, and then, both 136Thr and 136Ile variants have been positively maintained by natural selection in non-African populations.

The study by Sato and Kawata indicates that natural selection has possibly shaped our psychiatric traits and maintained its diversity. The results provide two important implications for human psychiatric evolution. First, through positive selection, the evolution from Asn to Thr at site 136 on SLC18A1 was favored by natural selection during the evolution from ancestral primates to humans, although individuals with 136Thr are more anxious and have more depressed minds.

Second, they showed that the two variants of 136Thr and 136Ile have been maintained by natural selection using several population genetic methods. Any form of natural selection that maintains genetic diversity within populations is called “balancing selection”. Individual differences in psychiatric traits can be observed in any human population, and some personality traits are also found in non-human primates. This suggests the possibility that a part of genetic diversity associated with personality traits and/or psychiatric disorders are maintained by balancing selection, although such selective pressure is often weak and difficult to detect.

https://neurosciencenews.com/personality-psychiatry-genetics-9820/

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Researchers led by Northwestern Engineering’s Luis Amaral sifted through data from more than 1.5 million questionnaire respondents to find at least four distinct clusters of personality types exist — average, reserved, self-centered, and role model — challenging existing paradigms in psychology.

“People have tried to classify personality types since Hippocrates’s time, but previous scientific literature has found that to be nonsense,”said co-author William Revelle, professor of psychology at Northwestern University’s Weinberg College of Arts and Sciences.

“Now, these data show there are higher densities of certain personality types,” said Revelle, who specializes in personality measurement, theory, and research.

The new study appears in Nature Human Behaviour. The findings potentially could be of interest to hiring managers and mental healthcare providers.

Initially, Revelle was skeptical of the study’s premise. The concept of personality types remains controversial in psychology, with hard scientific proof difficult to find. Previous attempts based on small research groups created results that often were not replicable.

“Personality types only existed in self-help literature and did not have a place in scientific journals,” said Amaral, Erastus Otis Haven Professor of Chemical and Biological Engineering at the McCormick School of Engineering. “Now, we think this will change because of this study.”

The new research combined an alternative computational approach with data from four questionnaires, attracting more than 1.5 million respondents from around the world. The questionnaires, developed by the research community over the decades, have between 44 and 300 questions. People voluntarily take the online quizzes, attracted by the opportunity to receive feedback about their own personality.

These data are now being made available to other researchers for independent analyses.

“A study with a dataset this large would not have been possible before the web,” Amaral said. “Previously, researchers would recruit undergrads on campus and maybe get a few hundred people. Now, we have all these online resources available, and data is being shared.”

Average

Average people are high in neuroticism and extraversion, while low in openness. “I would expect that the typical person would be in this cluster,” said Martin Gerlach, a postdoctoral fellow in Amaral’s lab and the paper’s first author. Females are more likely than males to fall into the Average type.

Reserved

The Reserved type is emotionally stable, but not open or neurotic. They are not particularly extraverted but are somewhat agreeable and conscientious.

Role Models

Role Models score low in neuroticism and high in all the other traits. The likelihood that someone is a role model increases dramatically with age. “These are people who are dependable and open to new ideas,” Amaral said. “These are good people to be in charge of things. In fact, life is easier if you have more dealings with role models.” More women than men are likely to be role models.

Self-Centered

Self-Centered people score very high in extraversion and below average in openness, agreeableness and conscientiousness. “These are people you don’t want to hang out with,” Revelle said. There is a very dramatic decrease in the number of self-centered types as people age, both with women and men.

The group’s first attempt to sort the data used traditional clustering algorithms, but that yielded inaccurate results, Amaral said.

“At first, they came to me with 16 personality types, and there’s enough literature that I’m aware of that says that’s ridiculous,” Revelle said. “I believed there were no types at all.”

He challenged Amaral and Gerlach to refine their data.

“Machine learning and data science are promising but can be seen as a little bit of a religion,” Amaral said. “You still need to test your results. We developed a new method to guide people to solve the clustering problem to test the findings.”

Their algorithm first searched for many clusters using traditional clustering methods, but then winnowed them down by imposing additional constraints. This procedure revealed the four groups they reported.

“The data came back, and they kept coming up with the same four clusters of higher density and at higher densities than you’d expect by chance, and you can show by replication that this is statistically unlikely,” Revelle said.

“I like data, and I believe these results,” he added. “The methodology is the main part of the paper’s contribution to science.”

To be sure the new clusters of types were accurate, the researchers used a notoriously self-centered group—teenaged boys—to validate their information.

“We know teen boys behave in self-centered ways,” Amaral said. “If the data were correct and sifted for demographics, they would they turn out to be the biggest cluster of people.”

Indeed, young males are overrepresented in the Self-Centered group, while females over 15 years old are vastly underrepresented.

Along with serving as a tool that can help mental health service providers assess for personality types with extreme traits, Amaral said the study’s results could be helpful for hiring managers looking to insure a potential candidate is a good fit or for people who are dating and looking for an appropriate partner.

And good news for parents of teenagers everywhere: As people mature, their personality types often shift. For instance, older people tend to be less neurotic yet more conscientious and agreeable than those under 20 years old.

“When we look at large groups of people, it’s clear there are trends, that some people may be changing some of these characteristics over time,” Amaral said. “This could be a subject of future research.”

This article has been republished from materials provided by Northwestern University. Note: material may have been edited for length and content. For further information, please contact the cited source.

Reference:

Martin Gerlach, Beatrice Farb, William Revelle, Luís A. Nunes Amaral. A robust data-driven approach identifies four personality types across four large data sets. Nature Human Behaviour, 2018; DOI: 10.1038/s41562-018-0419-z


Researchers have developed a new deep learning algorithm that can reveal your personality type, based on the Big Five personality trait model, by simply tracking eye movements.

t’s often been said that the eyes are the window to the soul, revealing what we think and how we feel. Now, new research reveals that your eyes may also be an indicator of your personality type, simply by the way they move.

Developed by the University of South Australia in partnership with the University of Stuttgart, Flinders University and the Max Planck Institute for Informatics in Germany, the research uses state-of-the-art machine-learning algorithms to demonstrate a link between personality and eye movements.

Findings show that people’s eye movements reveal whether they are sociable, conscientious or curious, with the algorithm software reliably recognising four of the Big Five personality traits: neuroticism, extroversion, agreeableness, and conscientiousness.

Researchers tracked the eye movements of 42 participants as they undertook everyday tasks around a university campus, and subsequently assessed their personality traits using well-established questionnaires.

UniSA’s Dr Tobias Loetscher says the study provides new links between previously under-investigated eye movements and personality traits and delivers important insights for emerging fields of social signal processing and social robotics.

“There’s certainly the potential for these findings to improve human-machine interactions,” Dr Loetscher says.

“People are always looking for improved, personalised services. However, today’s robots and computers are not socially aware, so they cannot adapt to non-verbal cues.

“This research provides opportunities to develop robots and computers so that they can become more natural, and better at interpreting human social signals.”

Dr Loetscher says the findings also provide an important bridge between tightly controlled laboratory studies and the study of natural eye movements in real-world environments.

“This research has tracked and measured the visual behaviour of people going about their everyday tasks, providing more natural responses than if they were in a lab.

“And thanks to our machine-learning approach, we not only validate the role of personality in explaining eye movement in everyday life, but also reveal new eye movement characteristics as predictors of personality traits.”

Original Research: Open access research for “Eye Movements During Everyday Behavior Predict Personality Traits” by Sabrina Hoppe, Tobias Loetscher, Stephanie A. Morey and Andreas Bulling in Frontiers in Human Neuroscience. Published April 14 2018.
doi:10.3389/fnhum.2018.00105

https://neurosciencenews.com/ai-personality-9621/

By Robert Preidt

In remote Italian villages nestled between the Mediterranean Sea and mountains lives a group of several hundred citizens over the age of 90. Researchers at the University of Rome La Sapienza and University of California San Diego School of Medicine have identified common psychological traits in members of this group.

The study, publishing in International Psychogeriatrics, found participants who were 90 to 101 years old had worse physical health, but better mental well-being than their younger family members ages 51 to 75.

“There have been a number of studies on very old adults, but they have mostly focused on genetics rather than their mental health or personalities,” said Dilip V. Jeste MD, senior author of the study, senior associate dean for the Center of Healthy Aging and Distinguished Professor of Psychiatry and Neurosciences at UC San Diego School of Medicine. “The main themes that emerged from our study, and appear to be the unique features associated with better mental health of this rural population, were positivity, work ethic, stubbornness and a strong bond with family, religion and land.”

There were 29 study participants from nine villages in the Cilento region of southern Italy. The researchers used quantitative rating scales for assessing mental and physical health, as well as qualitative interviews to gather personal narratives of the participants, including topics such as migrations, traumatic events and beliefs. Their children or other younger family members were also given the same rating scales and additionally asked to describe their impressions about the personality traits of their older relatives.

“The group’s love of their land is a common theme and gives them a purpose in life. Most of them are still working in their homes and on the land. They think, ‘This is my life and I’m not going to give it up,'” said Anna Scelzo, first author of the study with the Department of Mental Health and Substance Abuse in Chiavarese, Italy

Interview responses also suggested that the participants had considerable self-confidence and decision-making skills.

“This paradox of aging supports the notion that well-being and wisdom increase with aging even though physical health is failing,” said Jeste, also the Estelle and Edgar Levi Chair in Aging and director of the Sam and Rose Stein Institute for Research on Aging at UC San Diego.

Some direct quotes from the study’s interviews include:
•”I lost my beloved wife only a month ago and I am very sad for this. We were married for 70 years. I was close to her during all of her illness and I have felt very empty after her loss. But thanks to my sons, I am now recovering and feeling much better. I have four children, ten grandchildren and nine great-grandchildren. I have fought all my life and I am always ready for changes. I think changes bring life and give chances to grow.”
•”I am always thinking for the best. There is always a solution in life. This is what my father has taught me: to always face difficulties and hope for the best.”
•”I am always active. I do not know what stress is. Life is what it is and must be faced … always.”
•”If I have to say, I feel younger now than when I was young.”

“We also found that this group tended to be domineering, stubborn and needed a sense of control, which can be a desirable trait as they are true to their convictions and care less about what others think,” said Scelzo. “This tendency to control the environment suggests notable grit that is balanced by a need to adapt to changing circumstances.”

The researchers plan to follow the participants with multiple longitudinal assessments and compare biological associations with physical and psychological health.

“Studying the strategies of exceptionally long-lived and lived-well individuals, who not just survive but also thrive and flourish, enhances our understanding of health and functional capacities in all age groups,” said Jeste.

Study co-authors include: Salvatore Di Somma, University of Rome La Sapienza; David Brenner, Nicholas Schork and Lori Montross, UC San Diego; and Paola Antonini, 3B Biotech Research.

Story Source:

Materials provided by University of California – San Diego. Original written by Michelle Brubaker.

https://www.sciencedaily.com/releases/2017/12/171212091045.htm

Journal Reference:
1.Anna Scelzo, Salvatore Di Somma, Paola Antonini, Lori P. Montross, Nicholas Schork, David Brenner, Dilip V. Jeste. Mixed-methods quantitative–qualitative study of 29 nonagenarians and centenarians in rural Southern Italy: focus on positive psychological traits. International Psychogeriatrics, 2017; 1 DOI: 10.1017/S1041610217002721

Look at a photo of yourself as a teenager and, mistaken fashion choices aside, it’s likely you see traces of the same person with the same personality quirks as you are today. But whether or not you truly are the same person over a lifetime—and what that notion of personhood even means—is the subject of ongoing philosophical and psychology debate.

The longest personality study of all time, published in Psychology and Aging and recently highlighted by the British Psychological Society, suggests that over the course of a lifetime, just as your physical appearance changes and your cells are constantly replaced, your personality is also transformed beyond recognition.

The study begins with data from a 1950 survey of 1,208 14-year-olds in Scotland. Teachers were asked to use six questionnaires to rate the teenagers on six personality traits: self-confidence, perseverance, stability of moods, conscientiousness, originality, and desire to learn. Together, the results from these questionnaires were amalgamated into a rating for one trait, which was defined as “dependability.” More than six decades later, researchers tracked down 635 of the participants, and 174 agreed to repeat testing.

This time, aged 77 years old, the participants rated themselves on the six personality traits, and also nominated a close friend or relative to do the same. Overall, there was not much overlap from the questionnaires taken 63 years earlier. “Correlations suggested no significant stability of any of the 6 characteristics or their underlying factor, dependability, over the 63-year interval,” wrote the researchers. “We hypothesized that we would find evidence of personality stability over an even longer period of 63 years, but our correlations did not support this hypothesis,” they later added.

The findings were a surprise to researchers because previous personality studies, over shorter periods of time, seemed to show consistency. Studies over several decades, focusing on participants from childhood to middle age, or from middle age to older age, showed stable personality traits. But the most recent study, covering the longest period, suggests that personality stability is disrupted over time. “The longer the interval between two assessments of personality, the weaker the relationship between the two tends to be,” the researchers write. “Our results suggest that, when the interval is increased to as much as 63 years, there is hardly any relationship at all.”

Perhaps those who had impulsive character flaws as a teenager would be grateful that certain personality traits might even out later in life. But it’s disconcerting to think that your entire personality is transformed.

“Personality refers to an individual’s characteristic patterns of thought, emotion, and behavior, together with the psychological mechanisms—hidden or not—behind those patterns,” note the authors, quoting psychology professor David Funder’s definition.

If your patterns of thought, emotions, and behavior so drastically alter over the decades, can you truly be considered the same person in old age as you were as a teenager? This question ties in with broader theories about the nature of the self. For example, there is growing neuroscience research that supports the ancient Buddhist belief that our notion of a stable “self” is nothing more than an illusion.

Perhaps this won’t surprise you if you’ve had the experience of running into a very old friend from school, and found a completely different person from the child you remembered. This research suggests that, as the decades go by, your own younger self could be similarly unrecognizable.

You’re a completely different person at 14 and 77, the longest-running personality study ever has found

By David Robson

You might expect a great philosopher to look past our surface into the depths of the soul – but Ancient Greek thinkers were surprisingly concerned with appearance. Aristotle and his followers even compiled a volume of the ways that your looks could reflect your spirit.

“Soft hair indicates cowardice and coarse hair courage,” they wrote. Impudence, the treatise says, was evident in “bright, wise-open eyes with heavy blood-shot lids”; a broad nose, meanwhile, was a sign of laziness, like in cattle.

Sensuous, fleshy lips fared little better. The philosophers saw it as a sign of folly, “like an ass”, while those with especially thin mouths were thought to be proud, like lions.

Today, we are taught not to judge a book by its cover. But while it is wise not to set too much by appearances, psychologists are finding that your face offers a window on our deepest secrets. Even if you keep a stony poker face, your features can reveal details about your personality, your health, and your intelligence.

“The idea is that our biology, like genes and hormone levels, influences our growth, and the same mechanisms will also shape our character,” explains Carmen Lefevre at Northumbria University.

Consider the face’s bone structure – whether it is relatively short and wide or long and thin. Lefevre has found that people with higher levels of testosterone tend to be wider-faced with bigger cheekbones, and they are also more likely to have more assertive, and sometimes aggressive, personalities.

The link between face shape and dominance is surprisingly widespread, from capuchin monkeys – the wider the face, the more likely they are to hold a higher rank in the group’s hierarchy – to professional football players. Examining the 2010 World Cup, Keith Welker at the University of Boulder, Colorado, recently showed that the ratio of the width and height of the footballers’ faces predicted both the number of fouls among midfielders, and the number of goals scored by the forwards.

(To calculate this yourself, compare the distance from ear-to-ear with the distance between the top of your eyes, and your upper lip. The average ratio of width-to-height is around 2 – Abraham Lincoln was 1.93)

It may even clue you in to a politician’s motives. Using volunteers to rate former US presidents on different psychological attributes, Lefevre found that face shape seemed to reflect their perceived ambition and drive. John F Kennedy had a thicker-set face than 19th Century Chester Arthur, for instance. Such analyses of historical figures are perhaps best taken with a pinch of salt, however, and it has to be said that other traits, such as cooperation and intelligence, should be equally important for success.

As you might expect, your health and medical history are also written in your countenance – and the detail it offers is surprising. The amount of fat on your face, for instance, provides a stronger indication of your fitness than more standard measures, such as your body mass index. Those with thinner faces are less likely to suffer infections, and when they do, the illness is less severe; they also tend to have lower rates of depression and anxiety, probably because mental health is often closely related to the body’s fitness in general.

How could the plumpness of your cheeks say so much about you? Benedict Jones at the University of Glasgow thinks a new understanding of fat’s role in the body may help explain it. “How healthy you are isn’t so much about how much fat you have, but where you have that fat,” he says. Pear-shaped people, with more weight around the hips and bottom but slimmer torsos, tend to be healthier than “apples” with a spare tyre around the midriff, since the adipose tissue around the chest is thought to release inflammatory molecules that can damage the core organs. Perhaps the fullness of your face reflects the fatty deposits in the more harmful areas, Jones says. Or it could be that facial fat is itself dangerous for some reason.

Besides these more overt cues, very subtle differences in skin colour can also reveal your health secrets. Jones and Lefevre emphasise this has nothing to do with the tones associated with ethnicity, but barely-noticeable tints that may reflect differences in lifestyle. You appear to be in more robust health, for instance, if your skin has a slightly yellowish, golden tone. The pigments in question are called carotenoids, which, as the name suggest, can be found in orange and red fruit and veg. Carotenoids help build a healthy immune system, says Lefevre. “But when we’ve eaten enough, they layer in the skin and dye it yellow. We exhibit them, because we haven’t used them to battle illness.” The glow of health, in turn, contributes significantly to your physical attraction – more so, in fact, than the more overt tones that might accompany a trip to the tanning salon.

A blush of pink, meanwhile, should signal the good circulation that comes with an active lifestyle – and it might also be a sign of a woman’s fertility. Jones has found that women tend to adopt a slightly redder flush at the peak of the menstrual cycle, perhaps because estradiol, a sex hormone, leads the blood vessels in the cheek to dilate slightly. It may be one of many tiny shifts in appearance and behaviour that together make a woman slightly more attractive when she is most likely to conceive.

As Jones points out, these secrets were hiding in plain sight – yet we were slow to uncover them. At the very least, this knowledge helps restore the reputation of “physiognomy”, which has suffered a somewhat chequered reputation since Aristotle’s musings. Tudor king Henry VIII was so sceptical of the idea that he even banned quack “professors” from profiting from their readings, and its status took a second bashing in the early 20th Century, when it was associated with phrenology – the mistaken idea that lumps and bumps on your head can predict your behaviour.

But now the discipline is gaining credibility, we may find that there are many more surprises hiding in your selfies. Intriguingly, we seem to be able to predict intelligence from someone’s face with modest accuracy – though it’s not yet clear what specific cues make someone look smart. (Needless to say, it is not as simple as whether or not they wear glasses.) Others are examining the “gaydar”. We often can guess someone’s sexual orientation within a split-second, even when there are no stereotypical clues, but it’s still a mystery as to what we’re actually reading. Further research might explain exactly how we make these snap judgements.

It will also be interesting to see how the link between personality, lifestyle and appearance changes across the lifetime. One study managed to examine records of personality and appearance, following subjects from the 1930s to the 1990s. The scientists found that although baby-faced men tended to be less dominant in their youth, they grew to be more assertive as the years wore on – perhaps because they learnt to compensate for the expectations brought about by their puppyish appearance.

More intriguingly, the authors also found evidence of a “Dorian Gray effect” – where the ageing face began to reflect certain aspects of the personality that hadn’t been obvious when the people were younger. Women who had more attractive, sociable, personalities from adolescence to their 30s slowly started to climb in physical attractiveness, so that in their 50s they were considered better-looking than those who had been less personable but naturally prettier. One possibility is that they simply knew how to make the best of their appearance, and that their inner confidence was reflected on subtle differences in expression.

After all, there is so much more to our appearance than the bone structure and skin tone, as one particularly clever study recently demonstrated. The scientists asked volunteers to wear their favourite clothes, and then took a photo of their face. Even though the clothes themselves were not visible in the mugshots, impartial judges considered them to be considerably more attractive than other pictures of the participants. The finding is particularly striking, considering that they were asked to keep neutral expressions: somehow, the boosted self-esteem shone through anyway.

Our faces aren’t just the product of our biology. We can’t change our genes or our hormones – but by cultivating our personality and sense of self-worth, they may begin to mirror something far more important.

http://www.bbc.com/future/story/20150312-what-the-face-betrays-about-you

Sharks of the same species can have different personalities, indicates a new study published in the Journal of Fish Biology.

The study, led by Dr. Evan Byrnes of Macquarie University in North Ryde, Australia, examined interindividual personality differences between Port Jackson sharks (Heterodontus portusjacksoni).

Trials were designed to test the sharks’ boldness, which is a measure of their propensity to take risks, but also an influencer of individual health through its correlation with stress hormones and associated physiological profiles.

Port Jackson sharks were first introduced to a tank where they were provided with shelter, and timed to see how long it took for each shark to emerge from their refuge box into a new environment.

The second behavior test exposed each shark to handling stress, similar to handling by a fisherman, before releasing them again and observing how quickly they recovered.

The results demonstrated that each shark’s behavior was consistent over repeated trials, indicating ingrained behaviors rather than chance reactions.

That is, some sharks were consistently bolder than others, and the sharks that were the most reactive to handling stress in the first trial were also the most reactive in a second trial.

“This work shows that we cannot think of all sharks as the same,” Dr. Byrnes said.

“Each has its own preferences and behaviors, and it is likely that these differences influence how individuals interact with their habitat and other species.”

“We are excited about these results because they demonstrate that sharks are not just mindless machines. Just like humans, each shark is an individual with its unique preferences and behaviors,” said co-author Dr. Culum Brown, also from Macquarie University.

“Our results raise a number of questions about individual variation in the behavior of top predators and the ecological and management implications this may have. If each shark is an individual and doing its own thing, then clearly managing shark populations is much more complicated than we previously thought.”

“Understanding how personality influences variation in shark behavior – such as prey choice, habitat use and activity levels – is critical to better managing these top predators that play important ecological roles in marine ecosystems.”

_____

E.E. Byrnes & C. Brown. Individual personality differences in Port Jackson sharks Heterodontus portusjacksoni. Journal of Fish Biology, published online May 26, 2016; doi: 10.1111/jfb.12993