Are Intelligence and Personality Stable Across Adulthood and Into Old Age?
Kristin K. Lilienthal
PSY101: Introduction to Psychology
Instructor: Tiffani Edmunds

Are Intelligence and Personality Stable Across Adulthood and Into Old Age? Before a child is born the process of learning begins. A child learns to react to the sound of its parent’s voice, music, and even his mother’s feelings, and a little personality starts to develop. Once a child is born every moment of its day becomes a learning experience as he or she uses his senses to explore the world. How someone learns, retains what is learned, and one’s personality is shaped by life experiences and the knowledge gained from those experiences. Although there may be some changes in cognitive skills and personality as a person moves from middle to late adulthood, the reason for the change is not based on physical age, the changes are the result of the experiences of the individual. As an individual ages there are some natural stages and changes they often go through. Adolescence and young adulthood is a time where an individual starts to explore their identity and lifestyle and assert their independence from the family unit. Individuals may often enter this period under a “cognitive apprenticeship.” A cognitive apprenticeship is
“an instructional model wherein parents, siblings, other adults, and especially teachers serve as a combination of model, guide tutor, mentor, and coach to foster intellectual growth among learners (LeFrancois, 2011).”
During this time an individual may start building intimate relationships, developing social boundaries, and setting goals based on the knowledge and experiences he or she has gained up until this point in life. Once an adult reaches the middle adult years the focus may broaden from developing their own personal boundaries and relationships to accomplishing goals, and feeling like they are making a difference in the world. Individuals in this age range, approximately 25 to 65 years of age, may also find personal fulfillment by passing down the knowledge they have gained to a younger generation through mentoring, coaching a child’s sports team, or volunteering (Witt & Mossler, 2010). During middle adulthood cognitive skills continue to grow, but at a slower rate than childhood or as a young adult. According to K. Warner Schaie (1994), a person’s perceptual speed and simple mathematical computation ability declined during middle age (Perceptual speed actually starts to decline in early adulthood). The highest levels of functioning were in the areas of vocabulary, verbal memory, spatial orientation, and inductive reasoning (cited by Witt & Mossler, 2010). Short term memory (STM) and long term memory (LTM) also changes during middle adulthood. “Because STM is an active, conscious process, limited in both duration and capacity, it is easily disrupted by external events, as is clear every time we become distracted. LTM, on the other hand, is not easily disrupted (LeFrancois, 2011).”
STM can be easily interrupted by everyday distractions, like a phone call, an unexpected question, someone at the door. Even our own thoughts can interfere with STM, as anyone who has ever walked into a room and forgotten why they went in there, can tell you. LTM is not as easily disrupted as an adult reaches middle adulthood it may take longer to remember thing, but repetition, word association, and reflection. Memory and learning seem to go hand in hand, but they are actually separate functions. One can be taught something, and use that skill for a while, but may find that if the skill learned has not been used for a while, they are unable to recall how to do the task. This is not because the person did not learn the skill, but because it was not committed to the person’s LTM. Once something is learned and committed to LTM, it is not easily forgotten.
“Memory is involved in all aspects of human functioning. In fact, it is very difficult to separate memory and learning, so closely are they linked. Learning is a change in behavior that results from experience; and, in a sense, memory is the effect of experience. More precisely, it is the system that allows us to retain and retrieve the effects of experience (LeFrancois, 2011).” Fluid intelligence is developed as we learn and grow Fluid intelligence is the ability to use abstract reasoning to analyze information. According to Horn & Hofer (1992), Fluid intelligences includes the ability to see relationships, uses abstract reasoning and analyze information This differs from Crystallized intelligence which is our ability to use knowledge, experience, vocabulary and verbal memory. Fluid intelligence can decline with age, but crystallized intelligence continues to grow as an individual learns (cited by Witt & Mossler, 2010). It is noted by Witt & Mossler that the research carried out by Horn & Hoffer was conducted in a laboratory environment, and the adults were given specific tasks in a controlled situation. It is possible that the results of the study would be different if adults were observed in a natural setting, encountering normal day situations. A perceptual system made up of the sensory organs provides an individual with different kind s of information about the world. Each sensory system operates independently, but works together to provide the brain with information. (LeFrancois, 2011). A person’s taste buds and sense of smell often work together to tell the brain how something tastes. A piece of chewing gum may taste minty and sweet to the person chewing it, but happens to the taste of the gum if the person walks into a barn that houses livestock? The person chewing the gum may still taste some of the mint flavoring of the gum, but when the smell of the gum has been masked by the odor of the barn the gum “loses” some of its flavor, and the person may even report having the taste of the odor in their mouth. As a person gets older there is often a decline in the senses, poor eye sight, hearing loss, medications can interfere with the sense of taste or smell. The loss of one sense can greatly alter how a person perceives the world. It is often reported that when someone loses a sense, such as sight or hearing the other senses become heightened. A person who cannot see often seems to hear things around them better than a person who is relying on both sight and sound.

Merriam-Webster defines intelligence as “the ability to learn or understand things or to deal with new or difficult situations” If this is to believe to be true then intelligence cannot be measured simply by ones knowledge and cognitive abilities, and individuals personality will influence his or her ability to deal with new and/or difficult situations. Interactions with friends and family can play an important role in our intelligence. One often held belief regarding intelligence is that our level of intelligence is effected by our social interactions. Having a “positive personality” can lead to an increase of positive social interactions. The two main factors that make up a positive personality are personality adjustments and personality growth. These factors play separate and distinct roles in developing personalities. A study conducted at the International University in Bremen Germany showed that as a person ages adjustments in attitude increase based on experiences, however personality growth is rare (Staudinger & Kunzmann, 2005). This would indicate that once one reaches middle adulthood, if they already have what would be considered an outgoing or extroverted personality, they will more than likely continue to be outgoing, and however their attitude towards specific situations may change. According to Allemand & Hertzog (2007),
“It is possible that individuals who are disposed toward social engagement are more likely to experience benefits on integration to a larger social network with concomitant benefits for behavioral interaction patterns and adaptive recruitment of resources for a functional life style.” Older and hopefully wiser from the knowledge and wisdom gained through life’s lessons and experiences, an individual’s personality will start to solidify. LTM will allow a person to compare current experiences with lessons learned in younger years and make better decisions than what had been made in the past. As we mature our personality will also adjust to our lifestyle and current situation. According to Roberts, Walton, & Viechbauer (2006), we mature and become more confident about who we are and what we want in our middle adult years, this results in greater stability. “our personality also seems to change more in a positive direction as we mature, and we become "more confident, warm, responsible and calm (Roberts & Mroczek, 2008, p. 33).” Unfortunately, not everyone will experience the same increase in maturity, and confidence. As mention previously, the adjustments in attitude are based upon life experiences, if a person’s experiences and social interactions are not conducive to learning and personal growth they may never reach a point where they feel confident and secure in who they are. Better decision making that often accompanies middle and late adulthood, can change what brings satisfaction to a person. In middle adulthood a person is usually at the peak of their earning abilities, and will start focusing on preparing for retirement. During this time a person is more likely to report higher job satisfaction, positive work motivation, professional expertise, and responsibility. During this time work can become more interesting, and workers are often proud of their professional performance (Witt & Mossler, 2010). As a person enters into late adulthood, STM loss will increase. Anyone who has taken care of a parent or grandparent in their senior years, has more than likely experienced a situation where the senior could not tell them what they did that morning, but could tell a story about something that happened back in 1950. It is a well-known fact that as one gets older there will be some brain degeneration. Nearly all older adults experience some memory loss. “Older, stable memories are less likely to be forgotten than newer ones (Witt & Mossler, 2010).” More time and effort is needed to process new information as a person ages, especially when trying to learn a task that involves complex skills. However, if a task involves solving a “real-life” problem, the outcome will be more favorable. Relevant problem solving skills remain stable until late in life (Witt & Mossler, 2010). Asking grandpa to help you with a story problem on your math homework more than likely will not result in much help, however, asking grandpa to help you figure out what is wrong with your bicycle and how to fix could prove to be beneficial for both you and the bicycle. A 12-year study by Mroczek and Spiro “found that depression, hostility, anxiety, and anger are all tied to a higher incidence of sickness and disease. Form that one could conclude that, those who are happier, worry less, and are more thoughtful may experience better health than those who are more often angry, anxious, sad, and emotionally unstable” (Witt & Mossler, 2010). Better physical and emotional health can help an individual maintain a positive personality, and intelligence. However it is important to note, that the belief that intelligence and personality can be maintained throughout adult hood if the individual is willing to work for it. Studies showed that LTM can be maintained and new things can be learned, if the individual is willing to put the time to work on and develop new techniques for remembering. A persons personality can continue to adjust and adapt by making an effort to get out and experience new things, and meet new people. As a person transitions from middle adulthood into late adulthood, some cognitive skills are lost and there may be changes in personalities. However, in adults who are not suffering from Alzheimer’s disease or another form of dementia, changes in personality and intelligence are based on the actions and attitude of the individual and not an inevitable consequence of age.

References
Allemand, M., Zimprich, D., & Hertzog, C. (2007). Cross-Sectional Age Differences and Longitudinal Age Changes of Personality in Middle Adulthood and Old Age. Journal Of Personality, 75(2), 323-358. doi:10.1111/j.1467-6494.2006.00441.x. Retrieved from http://eds.a.ebscohost.com.proxy-library.ashford.edu
LeFrancois, G. (2011). Psychology: The Human Puzzle. San Diego, Bridgepoint Education, Inc. https://content.ashford.edu
Roberts, B., Walton, K., & Viechbauer, W. (2006). Pattern of mean-level change in personality traits across the life course: A meta-analysis of longitudinal studies. Psychological Bulletin, 132, 1–25. Retrieved from http://eds.a.ebscohost.com.proxy-library.ashford.edu
Staudinger, U. M., & Kunzmann, U. (2005). Positive Adult Personality Development: Adjustment and/or Growth?. European Psychologist, 10(4), 320-329. doi:10.1027/1016 9040.10.4.320. Retrieved from http://eds.a.ebscohost.com.proxy-library.ashford.edu
Witt, G. A., & Mossler, R. A. (2010) Adult dvelopment and life assessment. Retrieved from https://content.ashford.edu