Personality pathways of successful ageing

The world population of older adults has seen a dramatic rise in the recent past. The statistical figures are high and astonishing, number of people aged 60 and over is more than 800 million. The increase in figure is projected to be over 2 billion in 2050.[1] Multitude of social, demographic, psychological and biological factors contribute to a person's mental health status. Almost all these factors are particularly pertinent among older adults. In this background, emphasis has to be given to the successful ageing and quality of life in older adults. When we refer to ageing the psychosocial factors and individual factors both cannot be ignored. Among individual factors personality plays a very important role in determining the adjustment.

Personality has been noted to be playing an important role across all stages of life. Similarly adaptation in old age is also influenced by these dimensions. Biological changes may interfere with the brain's functioning. Social changes can lead to isolation or feelings of worthlessness. Hence personality is undeniably very important aspect of in successful ageing.[2]

Personality traits are relatively consistent, implicating that changes are not frequent and radical. However, change does occur over the long-term, because of naturalistic forces, such as physiological aging, or may be due to the intervention.[3,4] Personality refers to a core of relatively stable individual differences in which alterations can be intentionally induced or can occur naturalistically. Personality traits are considered phenotypic dimensions of human variation, reflecting both genetic and environmental influences. Twin studies converge on heritability estimates of major personality traits ranging from 40% to 50% respectively, with most of the remainder of variation attributable to non-shared environmental influences.[4,5,6]

STAGE THEORY OF PERSONALITY

There are specific challenges faced by older adults. Cultural and social milieu also have significant influence in adaptation to this stage of life. In Indian scenario the stage theory applied to stage of reclusion and aligning oneself to higher goals of life. Isolation and withdrawal from active engagement occurs in order to aligning oneself to higher goals of life. Cumming and Henry[7] suggested that older adults purposely withdraw from society. Disengagement occurs as older adults retire from work and decrease their social participation. The theory of disengagement reiterates that “although individuals differ, the expectation of death is universal and decrement of ability is probable. Therefore, a mutual severing of ties will take place between a person and others in his society.” Disengagement is a universal event, experienced across gender and cultures. On the contrary social psychologists offer the Activity theory, which suggests that healthy aging corresponds with continued psychological engagement and social participation throughout older age. Older adults should actively compensate for the age related changes in their biological, psychological and social experiences and individuals must continue to engage in and modify the activities that they pursued in their middle age. Research suggests that personality traits remain relatively stable over the life course.

The historical description of successful ageing by Havighurst describes as “adding life to the years” and “getting satisfaction from life.”[8] These notions were formalized into defining successful aging as having inner feelings of happiness and satisfaction with one's present and past life.[9] The idea of maximizing one's years, or getting the most out of life, evolved into a theory of continuity that suggests that successful aging might be best interpreted as continued participation in activities of middle age, maintaining midlife attitudes and adapting to new roles in order to maintain a positive sense of oneself. Maddox[10] later explained that the theme of active living refers to successful aging models. This model encourages older adults to maintain the same activities, social networks and behaviors that they engaged in throughout life. Together, these ideas shaped the current framework of successful aging that emphasizes both productivity and positive health outcomes in older age.

Rowe and Kahn[11,12] were the first researchers to distinguish between “usual aging,” characterized by normal decline in physical, social and cognitive functioning and “successful aging,” in which functional loss is minimized. They suggested that three criteria must be met for successful aging: (a) Absence of disease, disability and risk factors; (b) maintaining physical and mental functioning; and (c) active engagement with life. Although over the past decade categorizing older adults in this way (i.e., as aging “successfully” or “usually”) has been met with some degree of criticism the terminology of successful aging and its derivatives still maintained in gerontological literature.[13,14]

The Erickson's proposition about distinct stages which shape the personality, is contrasted by more contemporary psychological researchers, who have proposed that personality is defined as a set of traits that follow the individual throughout the life course.[15] The stages enumerated in by Erikson follow biologically driven events such as puberty and aging. In the domain of personality, factor approach was able to contribute significantly to genetics and environmental influences. The model of factor approach of personality emphasized, five traits which dispose an individual to particular thoughts, feelings and behaviors. These traits are: (a) Neuroticism, (b) extroversion, (c) openness to experience, (d) agreeableness and (e) conscientiousness. The research evidence of personality traits predicting a range of outcomes in aging, including health, longevity, noted trait of conscientiousness related with physical health, longevity, academic and occupational achievement, marital stability and mental health.[6] Conscientiousness is defined as a hierarchically organized units of traits that describe individual differences in the propensity to be self-controlled, responsible to others, hard-working, orderly and rule-bound. Factor analysis identified and replicated five lower-order facets of conscientiousness across studies: Impulse control, responsibility, orderliness, industriousness and conventionality.[16]

PERSONALITY AND HEALTH

There are some major research findings available in American literature particularly important have been the studies conducted at Duke University in North Carolina and at Baltimore. Furthermore of relevance are studies which were not originally designed to answer questions regarding ageing, but have continued long enough to be used for this purpose. Baltimore longitudinal studies of adult life and ageing, has now become the measure of choice in applied studies of personality.[17] Neuroticism is the personality trait that has been most often examined in conjunction with health behavior. It is defined as the tendency to experience negative emotions including anger, anxiety and depression. It has been connected with health behavior, principally in terms of heightened symptom report. It has also been suggested to be a risk factor heightening stress levels. However it is not necessarily a negative factor in the health context. It may lead to more frequent referral and thus early detection. Conscientiousness (c) is arguably the personality trait most likely to be implicated in health promoting behavior.[18]

In this context Baltimore Longitudinal Study on Aging (BLSA) is regarded as the most definitive study of personality traits. By analyzing long-term personality data, BLSA scientists learned, in fact, that an adult's personality generally doesn’t change much after age 30. People who are cheerful and assertive when they are 30 will likely be the same when they are 80. This research finding runs contrary to the popular belief that people naturally become cranky, depressed and withdrawn as they age. Paul Costa and Robert McCrae evaluated individuals between 19 and 80 years old for over 12 years and specifically measured their levels of neuroticism, extroversion, openness to experience, agreeableness and conscientiousness. And among the five factors model of personality conscientiousness has yielded stability across life span, Furthermore, trait stability especially characterized individuals after the age of 30.[19]

The unique aspect of this assumption was the influence of genetic factors in determining personality. The findings of Meta-analysis of genome-wide association studies (GWAS) of personality found one single nucleotide protein (SNP) that was associated with conscientiousness across multiple samples. Antonio Terracciano observed that, because of the many intervening factors between a SNP and a complex phenotype like trait conscientiousness, replication is difficult to achieve and these results are typical of GWAS approaches.[20] The interaction beween nature and nurture is rather explicitly proven finding.

Personality attributes of self-efficacy may act as a facilitator to successful ageing. Other psychological and social dimensions include one's adjustment to changes, being able to make choices and having friends and family.[21] Hence social engagement becomes very important dimension of successful ageing. Researchers have identified typology of personality and disease model and ignored the multidimensional approach to research on ageing.[22]

CONCLUSION

Personality trait is one of the factors influencing successful ageing. There are certain dimensions of personality trait remain stable over the life course and conscientiousness has been noted as one of the factors. The longitudinal study only can provide more conclusive evidence in this area.