From birth until old age, our memory skills continue to develop. At each stage of life, we add new skills, refine established ones, and build on our store of experiences and knowledge. The story of our memory throughout life is about change – but not necessarily about decline.
We remember little of what happened in our lives before the age of about three or four. This ‘ childhood amnesia’ is thought to be due to the fact that certain parts of the brain associated with memory are not mature in very young children. However, psychologists have demonstrated over the past few years that babies do have an active memory – although not for events. The mother’s voice and smell are immediately familiar, and newborn babies can recognize music that was played regularly to them while they were in the womb. The brain develops rapidly in the first few years, increasing the connections that affect memory processes. As well as building up procedural memories for skills, toddlers accumulate a store of knowledge about the way the world works. As children learn, they develop an understanding of their memory capacities. When asked how many items they will be able to remember from a tray of objects shown to them briefly, five typically say that they will recall more than they can in practice, while nine, ten- or ten–year–olds usually give a good estimate of their subsequent performance.
Memory at school
During school years, children develop more sophisticated memory skills in response to the demands made on them to learn and remember. They discover that information becomes easier to learn once it is organized, and chat repetition and practice strengthen memory for information. They also create associations between new and existing knowledge, which sets up different ways to access memory and also makes it easier to recall.
A growing interest in the world motivates young adolescents to invest more effort in learning what is important to them. New experiences occur almost every day, and they pay attention to nearly everything that comes their way – even if they subsequently lose interest in it. By their teens, most young people will have acquired a strong sense of their own physical and mental strengths and weaknesses and their potential for success in particular areas. As a result, they become more selective about the skills that they wish to improve on and the subjects that interest them most.
Adolescent schoolchildren are faced with the novel demands of study ing for formal examinations. At this stage, they begin to acquire strong rote-memory skills and develop different learning techniques for different memory tasks. The way they learn history or literature, for example, will differ from the way they learn scientific principles.
Young people are often motivated to learn by social goals, such as the desire to feel accepted by their peers and by their immediate seniors. They also want to learn the rules of the adult world so that they can obtain adult privileges. It is at this period, too, that adolescents often learn key skills – for example, how to move with confidence, how to negotiate with others, and how to plan and organize their work and social life. Social and physical skills such as these are usually uneducated, and teenagers have to work out for themselves how to acquire the necessary knowledge and expertise.
From young adulthood to middle age
Students who go on to higher education are expected to acquire knowledge in a variety of new and often very abstract disciplines. At college, they often learn information for which they may not have a great deal of use in later years unless they choose a career that is directly related to their degree subject. Such information must be applied as early as possible after leaving college if it is not to be forgotten. For example, modern language graduates will have to make a special effort to keep up their linguistic skills unless they work in one of the relatively few professions where these are primary requisites, such as translating or teaching.
Once they have embarked on their chosen career, young adults have to acquire and remember yet another new type of information: the specialist knowledge and skills required for their work. In many careers – even those where some job-related skills are taught on training courses – they are unlikely to face exams and must rely on their day-to-day application of the new knowledge ‘on the job’ to make it stick. With practice, though, people become better and better at remembering the type of specialist information that goes with their job.
Because they have had more practice, older workers in any given career usually assimilate new specialist information more quickly and in greater quantity than their younger colleagues. The repeated use over many years of information or skills acquired early in one’s career also means that employees nearing retirement often show no decline in performance compared with their juniors – older typists, for example, have been found to be just as fast as young ones.
The later years
Even if retirement involves a complete break from career work, learning is far from over, and we continue to build and store information in memory throughout our senior years. With retirement, for example, may come the need to learn numerous practical skills, such as how to manage reduced finances and health. There is also the question of how to organize the increased amount of leisure time without work-centered routines. Many older people pursue interests that they did not have time for before.
Research has shown that people do not generally experience a decline in overall memory function before their fifties or sixties. Past this age, some decline in memory skills is inevitable as a natural part of the aging process, but some growth may occur as well. As a rule, older people increase those memory skills that they actively use.
Memory changes
Recent studies have led to a better understanding of the complex way in which memory changes with age. Some older people have trouble with memory tasks either because their memory skills have become rusty or because they never acquired them in the first place. Tasks that younger people may find stimulating, such as learning to use a video machine, often present difficulties to older people. It may be that older people encounter novel stimuli less often and are more daunted when faced with something new – a younger person, for whom new stimuli are an almost daily occurrence, is less surprised, and so learns readily. Or it may be that an older person is less interested.
Other explanations are based on changes in intelligence in older people. One idea is that there are two types of intelligence: ‘crystallized intelligence, ‘which is based on acquired knowledge and skills, and ‘fluid intelligence, which we use to handle unfamiliar tasks. The theory is that while crystallized intelligence may be enhanced throughout active adulthood, fluid intelligence may deteriorate.
Like most people, older people recall recent events with little difficulty, but they typically find that they can remember their youth better than the intervening years. Childhood and youth are full of new experiences, from a first plane flight and public exams to a first kiss and first day at work – experiences that seize our attention, fix themselves in memory, and put their stamp on each passing year. As we get older, the tally of birthdays, holidays, and minor successes at work mounts up, and each of these events becomes less remarkable to us and less memorable as a result. This is why, as we get older, we sometimes complain that the years seem to ‘fly past.’
Measuring Memory
Sir Francis Gaitan, an eminent 19th century scientist, was a pioneer in the measurement of individual mental capabilities. He devised a technique for testing autobiographical memory in which a person was given a ‘cue word ‘and then asked to relate all the recollections that this word brought to mind. These were rated for characteristics such as vividness and level of detail. Galton’s findings – that older people typically recalled things from their early life, while younger people recalled much more recent events – still hold.
New toys
Learning the tricks of a new piece of equipment such as a mobile phone can be a positive joy to a young person but a bit of a chore in later life. Usually, older people need more practice, which is why they may still refer to the manual long after a teenager has mastered the technology.
