Nearly 1.3 million people passed through American airports last Sunday alone, despite warnings from health experts that flying to and from holiday destinations would cause a further surge in the coronavirus.

Those who traveled did so to the backdrop of more than 330,000 COVID-19 deaths — according to the Johns Hopkins Coronavirus Resource Center — many caused by the well-reported spike in COVID-19 cases following Thanksgiving holiday travel.

To those isolated at home — and particularly the elderly and vulnerable — the behavior of their fellow Americans appeared irrational at the least and selfish at the most.

Nevertheless our airports were full.

There is an axiom in clinical psychology circles: Every behavior is believed to have a rationale that supports it. What that means is that what is rational for one person may not appear so to another.

It means that the person who has chosen to travel has a belief — typically a very strong belief — that their physical and safety needs are being managed and therefore their need for family deserves attention.

Such thinking follows Maslow’s Hierarchy of Needs, a psychological theory that states we have a seven-tier pyramid of needs from basic (physical) through safety onto love and belonging, and so forth.

Maslow’s needs are generalizations that overwhelmingly apply. But they do not always follow external rational logic. Self-identity, religious feelings or political partisan beliefs may, on occasion, override lower needs.

The need to maintain family tradition may override or bend beliefs about safety. If we rationalize away the lower-tier need, we can turn our attention to needs higher up, such as love and belonging.

This appears to be the case in many who chose to travel.

There are other psychological theories or principles that come into play as well in directing our behavior. As deprivation increases, our focus on basic needs becomes stronger.

Hunger is an obvious example. Sex is another as well as touch, which is especially in our awareness during the pandemic.

Each of these are needs made all the more salient during periods of deprivation. Grandparents want to hug their grandchildren, husband and wives eagerly await the touch of their spouse when one lies in a hospital bed.

We all want the hugs of those we love. These feelings rose to the top of the needs hierarchy of those who traveled — magnified by COVID-19 fatigue.

The timing of a reward or punishment played a critical role in our decisions concerning coronavirus risk. The fact that the coronavirus does not show immediate consequence has been critical in our population not complying to medical recommendations.

If the virus caused immediate dire symptoms, there would be no one traveling. Additionally, most of us know people who tested positive but experienced mild symptoms.

Knowing that others have traveled without immediate illness bends our tendency to perceive this as appropriate behavior. They may eventually develop symptoms, but we don’t see them.

Deciding to travel during a holiday season is ultimately made as a value perception of what is safe and what is important. Those who chose to travel, despite evidence others would dispute, believe that they could do so safely.

They then moved onto their need for love and belonging. In their minds, they were behaving rationally.

Others, looking at their own risk factors and information, believed the travelers were making excuses in deciding to enact crazy behavior, taking senseless risk.

Each of us perceives the world through our own lens. Understanding others actions may not make sense from our perspective, but then again ours does not make sense to them.

During this period when we are so divided, we may not condone or agree with each other’s thinking. It may be useful to at least understand the rationale of others.