The “Social Portfolio” is a simple but excellent idea concocted by the late Gene Cohen, who was a gerontologist at George Washington University.

He was thinking about how people spend their time in their older years, and in particular how, as we get older and older, we often become more isolated and have less and less to do. He attributes this to two typical realities:

• If we live into ripe old age, we outlive many of our dearest companions. Or because of lack of mobility (theirs or ours), we lose touch with them. Or because of disabilities (theirs or ours), we can no longer engage with them in the ways we used to.
• As we age, we tend lose energy or mobility, or both. This limits what we can do in the way of purposeful activity, or even leisure activities.

To prepare for these problems, and thereby overcome them, Cohen suggests that we construct a “social portfolio” in four groups: activities we pursue with others and activities we pursue alone, and for each of those, activities that require high energy or high mobility, and those that don’t. The object is to make sure we have a few pursuits in each of these four categories that truly engage us.

If we do, then as we age, and we lose access to some of our best companions, we can gradually pivot to those pursuits that we can do alone. As we become less energetic or less mobile, we can focus on activities that do not require these capabilities.

In theory, we could wait until we got to that stage before we developed new interests. But in reality, that’s usually too late. It takes a while to develop new interests. You have to invest in creating a base of knowledge or skill before most things really grab hold of you. And you might have to try quite a few different things before you find two or three that you really fall for. All of that takes energy (which you may not have, if you wait). And it’s easier to develop such interests while you still have good friends around who might involve you in some of their interests. Expanding your social portfolio now is really the best way to go.

In addition, a more diverse, balanced life is usually best for people of all ages. If you list your main current activities in Cohen’s four categories, there’s a good chance you’ll find that most of them fall into the same one or two sectors. Your life would probably be more interesting and fulfilling if this were not the case, and your interests were more evenly spread. Another reason to start now.

The way to start is exactly what I just mentioned. Make lists of the ways you currently like to spend your time, whether in purposeful or leisure activity, in each of these four groups. Then, for any group that is empty, or has only one item in it, see if you can’t think of at least one or two new activities that you could try out.

For example:

• High-energy activities you do with others include competitive sports, performance arts, coaching or teaching physically demanding activities, and travel.
• High-energy activities you do alone also include a variety of sports and games, as well as various forms of individual exercise, along with outdoor activities such as gardening, walking, etc.
• Low-energy activities you do with others include taking classes, being a spectator at public events, hobbies and games that you do with other people, private socializing with others, and interacting online.
• Low-energy activities you do mainly alone include reading and self-study, games and puzzles, letter-writing, pursuing an at-home hobby, doing simple exercises, relaxing with television or video or computer games or websites, and also private contemplation, meditation, or prayer.

Note that most solo activities are also things you can do with others, and so you can ask friends and family members what they do in your weak categories, and maybe they can introduce you to one or two new interests. And maybe you can do the same for them.

For more thoughts about the idea of a social portfolio, and links to resources you can use for ideas about how to expand your own social portfolio, go to: www.RetirementWorks2.com/RetireReady/RW_RetireReady_Avocation.htm.

Chuck Yanikoski is a retirement adviser who lives and works in Harvard. For more about him, or to contact him directly, visit www.ChuckYRetirement.com.