Can my Big 5 Change?

Yes

Whilst a certain degree of development with age is outlined in the MBTI orthodoxy (e.g. the development of functions) one of the fundamental rules seems to be that a person will never change their MBTI type. Once your type is established you will be that type until you die. This is another instance where MBTI users apply MBTI logic to the big 5 and expect it to follow the same principles. They ask "can my big 5 type change?" as if there is something surprising or counter-intuitive about the idea that someone's personality can change over time. SLOAN types are simply a summary of your big 5 scores. It is not unusual for big 5 scores to change over time. If your scores change, your SLOAN type can change. There is no assumption that your SLOAN type is a category that will follow you to the grave.

Big 5 tests simply measure how you think and feel and behave at the moment that you take the test. You can probably assume that the answers you give on a test today will not be identical to the answers you would give in 30 years time. On an individual level someone may change dramatically over the course of their life or they may not change at all. But when we examine a population we find that change tends to follow certain patterns.

Population Level Trends

People on average tend to see certain traits shift in the same direction. Traits don't always develop in a linear direction. A trait may rise up until mid life and then decline in later life. There are also some cross sex differences in the trends. This is a rather complex area of study where much of the data shows very subtle or contradictory trends so this page will just briefly summarise the most general trends that have been observed.

Openness: No clear pattern. Some studies indicate a decrease with age, some indicate an increase. Some studies note sex differences in trends.

Conscientiousness: Some studies show a decline from childhood into adolescence. There appears to be a strong consensus that Conscientiousness increases from adolescence into adulthood. The picture for later life is ambiguous with some data suggesting that conscientiousness decreases after mid-life and some showing an increase in later life.

Extraversion: Ambiguous. Some studies suggest a decline from childhood to adolescence. Some suggest that Extraversion is stable throughout adulthood, some that it declines consistently and significantly across adulthood.

Agreeableness: That Agreeableness increases after adolescence and is unlikely to decrease is one of the most well established trends. The increase however appears to be subtle and the period of life during which the increase occurs (e.g. Young adulthood vs old age) is contested.

Neuroticism: Generally Neuroticism is believed to decrease from adolescence to adulthood although some studies contradict this finding. Sex differences in trends have been noted.

The overall picture for population level trends seems to be highly ambiguous. The least contested claims seem to be:
1. Adults tend to be more Conscientious than teenagers.
2. Extraversion does not increase during adulthood.
3. Agreeableness does not decrease during adulthood and will probably have increased by the time later life is reached.

Summary

None of these trends will dictate how your personality will change over time. These are general trends noted at a population level but you are an individual. Your trend is likely to follow the general trend. If you are a teenager then you are likely to become more conscientious. If you are an adult you are likely to become more agreeable. But your trend might go in the opposite direction. Population level trends merely suggest the likely course for an individual but there are individuals whose natural development follows no established trend. The main thing to take away from this article is that your SLOAN type is not the same as your MBTI type. It may well change in the years to come.