Imagine for a moment supposing you didn't have a birth certificate and that your age was determined only by how you felt on the inside. What age do you think you are?

The number of years that have transpired since your birth is an immutable truth, just like your height or shoe size. However, our daily lives imply that we don't always see aging in the same manner, with many people believing they are younger or older than they actually are.

This trait is becoming more and more interesting to scientists. According to their research, your "subjective age" may be crucial to comprehending why some people seem to flourish as they age, while others seem to diminish. "Important daily decisions may be made based on how much older folks feel much younger than they are.

It has taken decades to get at this new knowledge of the aging process. In the 1970s and 1980s, some of the initial research illustrating the difference between felt and chronological age first published. Initially there was a trickle of curiosity, but now there is a flood. Over the past ten years, a deluge of fresh research has examined the potential psychological and physiological effects of this disparity.

This research has studied how our personality interacts with subjective age, which has proven to be one of the most fascinating areas of study. It is now widely acknowledged that people soften with age, becoming less outgoing and open to new experiences. These personality changes are more prominent in older people than in younger people.

 #1. Having a lower subjective age doesn't leave us frozen in a state of permanent 

However, it's interesting to note that those who had younger subjective ages also showed signs of typical aging, such as becoming more conscientious and less neurotic. As a result, they continue to appear to develop the wisdom that comes with more life experience. But it doesn't take away from the vigor and enthusiasm of youth. It's not as though having a lower subjective age renders us permanently immature.

As we age, feeling younger than our years appears to be associated with a decreased risk of depression and higher mental wellbeing. Additionally, it translates to greater physical health, a reduction in dementia risk, and a lower likelihood of being admitted to the hospital due to illness. 

More than 17,000 middle-aged and elderly people were followed throughout the course of three longitudinal investigations.

The majority of respondents thought they were roughly eight years younger than they actually were. However, several people thought they had aged, and the effects were severe. Even when you account for other demographic factors like education, race, and marital status, feeling 8 to 13 years older than your actual age was associated with an 18 to 25% higher risk of death throughout the course of the research periods and a heavier burden of disease.

#2.Subjective age reveals so much about our health for a variety of factors.

If your subjective age is lower as you get older, you can find that you enjoy a wider variety of activities (like traveling or picking up a new interest) as a direct result of those accompanying personality changes. According to studies, perceived age is a predictor of physical activity patterns, for instance, says Stephan.

However, the process that connects physical and mental health to subjective age very definitely works both ways. You may feel older if you have depression, forgetfulness, or physical vulnerabilities. It may lead to a vicious cycle in which psychological and physical variables simultaneously increase our perception of age, worsen our health, and make us feel even older.

#3.subjective ageing appears to occur on Mars, where one Earth decade 

equals only 5.3 Martian years

According to a nuanced study by Anna Kornadt at Bielefeld University in Germany, some psychologists have hypothesized that a lower subjective age is a form of self-defence that shields us from the unfavorable age stereotypes.

The study by Kornadt was predicated on the hypothesis that people's subjective ages may be complex and vary across domains. When you consider yourself at work vs when you consider your social ties, for instance, you could experience distinct emotions. In order to find out whether participants felt younger or older than they actually were in various life domains, Kornadt asked them to respond.

She discovered that, as expected, when negative age stereotypes are most pervasive, such as in the areas of employment, health, and finance, people's subjective ages were lower to bolster the claim that this way of thinking enables individuals to separate themselves from the negative stereotypes associated with their age group. If you truly believe, "I may be 65, but I only feel 50," you won't be as concerned about, say, how well you do at work. Kornadt discovered that those with lower subjective ages had a tendency to have more optimistic future self perceptions.

Despite these advances, scientists are only getting to grips with their potential implications, though it is certainly possible that future interventions might try to reduce participants’ subjective age and improve their health as a result. In one of the few existing studies, elderly participants in a fitness regime , if the experimenters praised their performance relative to other people of their age.

And given its predictive power – beyond our actual chronological age – Stephan believes that doctors should be asking all their patients about their subjective age to identify the people who are most at risk of future health problems to plan their existing health care more effectively.