It’s been 48 years since James David Barber, then chairman of the political science department at Duke, published his seminal treatise, The Presidential Character: Predicting Performance in the White House. The book is largely forgotten today, but it caused quite a stir when it appeared in 1972. Barber, who died in 2004, looked at qualities of temperament and personality in assessing how the country’s chief executives approached the presidency—and how that in turn contributed to their success or failure in office.

By extension, Barber’s prism of assessing presidential character also could be used to predict how particular politicians might approach the White House job should they ever attain it.

I last wrote about the Barber thesis in The National Interest magazine back in 2013 in assessing the temperament and outlook of President Barack Obama (reprinted on the same website a year later as a kind of update), and I reprise here some of the language I employed then to describe the Barber concept. I do so as a foundation for assessing the presidential character of President Trump and (prospectively) of his presumptive opponent, former Vice President Joe Biden.

Barber assessed presidents based on two indices: first, whether they were “positive” or “negative” in outlook; and, second, whether they were “active” or “passive” in ambition. The first index–the positive/negative one–assesses how presidents regard themselves in relation to the challenges of the office; so, for example, did they embrace the job with a joyful optimism or regard it as a necessary martyrdom they must sustain in order to prove their own self-worth? The second index—active vs. passive—measures their degree of wanting to accomplish big things or retreat into a reactive governing mode.

The two indices produce four categories of presidents, to wit:

Active-Positive: Presidents with big national ambitions who are self-confident, flexible, optimistic, joyful in the exercise of power, possessing a certain philosophical detachment toward what they regard as a great game.

Active-Negative: Compulsive people with low self-esteem, seekers of power as a means of self-actualization, given to rigidity and pessimism, driven, sometimes overly aggressive. But they harbor big dreams for bringing about accomplishments of large historical scope.

Passive-Positive: Compliant presidents who react to events rather than initiating them. They want to be loved and are thus ingratiating—and easily manipulated. They are “superficially optimistic” and harbor generally modest ambitions for their presidential years. But they are healthy in both ego and self-esteem.

Passive-Negative: Withdrawn politicians with low self-esteem and little zest for the give-and-take of politics and the glad-handing requirements of the game. They avoid conflict and take no joy in the uses of power. They tend to get themselves boxed up through a preoccupation with principles, rules, and procedures.

When Barber first put forth this matrix, he was correctly viewed as distinctively probing and original. And there is little doubt that Barber’s perceived  traits, if correctly identified and analyzed, can inform our assessments of how presidents do their job—or how prospective presidents might do theirs. But there is plenty of room for debate when it comes to attaching particular traits to particular presidents.

For example, Barber identifies George Washington as Passive-Negative, meaning he had low self-esteem, shunned opportunities for taking power, retreated from conflict, and was generally preoccupied on small matters at the expense of big ambitions. This hardly squares with history’s consistent portrayal of the first president. Another example was Barber’s categorization of Ronald Reagan as Passive-Positive, meaning his famous optimism was merely superficial, that he reacted to events rather than initiating them, and was easily manipulated.

This Reagan portrayal may have comported with what many of his opponents and detractors thought of him during his presidential tenure, but it doesn’t fit the real Reagan, who reversed decades of orthodoxy to transform the country’s economic debate and set out not just to counter the Soviet threat but to actually upend the Soviet Union itself. And he did this with hardly any evidence that he absorbed in any unhealthy way the barrage of harsh criticism thrown at him.

On the other hand, Lyndon Johnson and Richard Nixon clearly were Active-Negative, as Barber suggests. So were Herbert Hoover and Woodrow Wilson. And it isn’t difficult to accept some of Barber’s Active-Positive categorizations—Thomas Jefferson, Franklin Roosevelt, and Harry Truman, for example. All this suggests that there is plenty of room for discussion and debate on just where various presidents should be placed. It’s a kind of parlor game. And no doubt partisan impulses will creep into the parlor game as well.

So let’s go into the parlor and talk about Trump and Biden.

It isn’t difficult to place Trump on the Active-Passive scale. He is a man of large ambitions, as evidenced by his intent, as a 2016 candidate for the Republican presidential nomination, to mow down the entire GOP establishment on his way to the party nod. As president he has embraced a similar resolve to take the country in an entirely new direction in a host of areas—immigration, trade, foreign affairs. Thus it seems clear he is an Active president in his resolve, often expressed in audacious terms, to change American society in very significant ways.

But is he a Negative or a Positive? The Positive presidents relished the job and the grand necessity to move events by persuading, cajoling, bargaining with and perhaps occasionally threatening other players in the political arena. The great Active-Positive presidents all had fun in the job. They showed a zest and enthusiasm that was infectious, not just with the American people but also with members of Congress.

This doesn’t describe Trump. There’s no look of the happy warrior about him but rather a consistent bitterness and whininess. He demonstrates hardly any zest for the job and certainly very little enthusiasm for dealing with, cajoling, influencing, or even outmaneuvering the political opposition. The result is that he seldom outmaneuvers his adversaries at all.

And probably no president in American history has done more to make the big issues of the day about himself and his fate rather than about the nation and its fate. This is a bit of a giveaway that his struggles are driven by internal motivations, perhaps even internal demons of some kind or other.

All this helps explain why Trump has been unable to build politically on his basic fount of support—the 39 percent to 43 percent of Americans who give him a positive performance rating. If there is one thing his political style is not, it’s infectious. His negativity is a barrier to expansion in his overall public support; his inability to expand his public support is a barrier to success in governance; and his lack of success in governance is a barrier to eventual political success in November.

Thus do we see that Trump seems to be an Active-Negative. Presidents in this Barber category don’t have great track records. They include John Adams, a failed one-termer; Woodrow Wilson, a two-termer whose second term was among the most disastrous of our history; Herbert Hoover, tossed out after a single term because he couldn’t find a way to grapple with the Great Depression; Lyndon Johnson, a foreign-policy failure of rare dimension; and Richard Nixon, the only president to resign the office in disgrace.

What about Biden? Of course, using the Barber analyletical tool to assess the presidential character of someone who has never been president has to be considered a qualified enterprise at best. But the man has been at a high level on the national political scene for nearly half a century, and in that time we have been given a solid opportunity to observe him and assess his political attributes.

On the Positive/Negative scale, Biden would seem to be a Positive. He was excoriated early in the Democratic nomination battle for touting his ability over the years to work with fellow senators who had demonstrated their segregationist prejudices, including Mississippi’s James O. Eastland and Georgia’s Herman Talmadge. “We didn’t agree on much of anything,” said Biden, adding however, “We got things done.”

The outcry, much of it mean-spirited, was predictable, but Biden’s ability to work with senatorial colleagues was a hallmark of his image over the decades of his congressional tenure. The highly regarded Congressional Quarterly book of political profiles, Politics in America, praised Biden for his ability to work with North Carolina Republican Jesse Helms when Helms was chairman of the Foreign Relations Committee and Biden was its ranking member. Said the book: “Biden’s ability to maintain lines of communication with all groups often has made him, rather than Helms, the key vote on Foreign Relations.”

This can be viewed as evidence of a Positive trait, based on the Barber scale. Even after 30 years in the Senate, said Politics in America, “he still exhibits the intelligence, drive and passion of his youth.” The key word here, in terms of presidential character, is “passion.” Positives demonstrate a zest for the job and an openness to people, even those in the opposition who represent impediments to success that must be dealt with through persuasion, cajolery, back-slapping, and old-fashioned horse-trading. Positives love that game; so does Biden.

On the Active/Passive scale, Biden seems to tilt toward passivity. This is difficult to assess, however, because you can’t know how a president will view the White House job with any definiteness until he or she actually becomes president. But Biden’s long Washington service reveals an adroit legislative politician who dealt with issues as they emerged, without much evidence of vision or big thinking.

Thus does it appear that Biden represents a likely Passive/Positive president. Recall, Barber sees presidents in this category as wanting to be loved and thus ingratiating—and easily manipulated. That indeed is one of the knocks on Biden by conservatives—that he is being manipulated in his campaign, and would continue to be as president, by his party’s emergent leftist radicals.

In any event, we have—for whatever it might be worth—what appears to be Biden’s Passive/Positive persona up against Trump’s more definitive Active/Negative designation. This isn’t intended as a suggestion on how anyone should vote, merely as one small window on the race as it unfolds.

Robert W. Merry, longtime Washington, D.C., journalist and publishing executive, is the author of Where They Stand: The American Presidents in the Eyes of Voters and Historians, among other books.