In President Biden’s telling, he was a teenage civil rights activist, a former trucker, the first in his family to go to college and the nephew of a cannibalism victim.

All of these claims stretch the truth or are downright false. But Mr. Biden persists in telling personal tales with rhetorical flourishes and factual liberty when he works a room or regales an audience. They are a way to connect with voters, emphasize his “middle-class Joe” persona and charm his audience.

Despite Mr. Biden’s penchant for exaggerating details when recounting episodes from his life, these autobiographical embellishments differ in scale and significance from the stream of lies about a stolen election peddled by his opponent, former President Donald J. Trump.

A White House spokesman, Andrew Bates, said that Mr. Biden had “brought honesty and integrity back to the White House” and that he shared life experiences that had shaped his outlook.

Connecting with his audience through hyperbole

WHAT WAS SAID

“In our last debate, when I was 29 years old, the first question he was asked at the debate was, ‘Do you have any regrets, Senator Boggs?’ And he said, ‘No.’ Then we came to the very end of the debate, where I spoke and then he was to conclude. He stood up, and he said, ‘You know, I was asked if I had any regrets. I said no, but I have one: Had Joe Biden gone to the Naval Academy when I appointed him, he’d still have seven months left on and wouldn’t be able to run.’”
— in a May commencement speech at West Point Military Academy

Mr. Biden has repeatedly recounted this tale to graduating cadets at various military academies and to families of service members: In high school in the 1960s, he had been nominated to attend the United States Naval Academy by Senator J. Caleb Boggs of Delaware, his Republican opponent in his first Senate race. Mr. Boggs, Mr. Biden sometimes adds, later lamented that Mr. Biden had declined to accept the nomination in a 1972 debate. It is an anecdote that dates as far back as 2010, when Mr. Biden said in a speech that Mr. Boggs had “considered” him for the academy.

It is possible that this nomination occurred, but The New York Times could not verify Mr. Biden’s claim.

The academy does not have any records of Mr. Biden receiving a nomination or an appointment, said a spokeswoman, Ashley Hockycko, but it does not possess preliminary applications or requests made to congressional offices.

Similarly, The Times was unable to verify Mr. Biden’s retelling of that 1972 debate. Newspaper articles detailing debates and events attended by Mr. Biden and Mr. Boggs in September and October of that year did not mention any questions about regrets or the nomination. In his 2007 autobiography, “Promises to Keep,” Mr. Biden wrote of only one debate, and did not include any reference to the nomination.

It is also unclear what Mr. Boggs, in Mr. Biden’s telling, could have meant by suggesting Mr. Biden would have still been committed to the academy or the armed services for another seven months. Midshipmen at the Naval Academy attend for four years and serve for at least five years in the Navy or Marines after graduation. Had Mr. Biden attended the academy instead of the University of Delaware in 1961, he would have still been able to run against Mr. Boggs in 1972.

WHAT WAS SAID

“I used to drive an 18-wheeler.”
— at an April campaign event in Florida

Mr. Biden often repeats this claim when attending events with union members. The White House cited Mr. Biden’s job driving a school bus during law school. In the 1970s, he also took a 500-mile trip as a senator on a cargo truck.

WHAT WAS SAID

“As a matter of fact, the first organization I ever joined was the N.A.A.C.P. Didn’t get to vote until you were 21 in those days, but I got involved in civil rights when I was 15.”
— at an N.A.A.C.P. event in Michigan in May

— in an interview with Howard Stern in April

For decades, Mr. Biden has occasionally suggested that he played a greater role in the civil rights movement than he actually did. While there is corroboration of Mr. Biden’s participation in a few desegregation events, he has also said he would not consider himself an activist in the movement. There is no evidence that he was ever arrested.

The White House said that there are countless moments in any person’s life that local newspapers opt not to cover and that Mr. Biden was proud to have stood up against segregation in his youth.

The Washington Post detailed several other instances of the anecdote Mr. Biden is relaying, through his mother, of his arrest as a teenager while protesting for civil rights. In some cases, Mr. Biden has said he was 13 or that the police brought him home.

Local newspapers reported that in spring 1959, when Mr. Biden was 16, a Black family moved into an all-white neighborhood in Wilmington, prompting residents to protest against integration. Police officers described the demonstrators as a mob, some armed with fire bombs, and arrested seven people, including four teenagers for possessing fireworks. (The house was bombed and destroyed later that year.)

Mr. Biden joined the N.A.A.C.P. during his first political race for New Castle County Council in 1970, when he was in his late 20s, according to a 2019 Washington Post article that included an interview with the former president of the Delaware N.A.A.C.P.

Highlighting and exaggerating his middle-class roots

WHAT WAS SAID

“I’m the first in my family ever to go to college.”
— at a May campaign event in Detroit

Mr. Biden described his maternal grandfather, Ambrose Finnegan Sr., as the “only person in the house with a college degree” in his 2007 autobiography. According to Mr. Finnegan’s 1957 obituary, he attended and played football for Santa Clara College in California. Mr. Biden has previously said that he was the first on the Biden side of the family to go to college.

WHAT WAS SAID

“Under my plan, nobody earning less than $400,000 will pay an additional penny. I hope you’re all able to make $400,000. I never did.”
— at an April campaign event in Pennsylvania

“She said, ‘Did you read today’s paper?’ I said, ‘They don’t have today’s paper — Wilmington paper, Delaware — where I’m with Leahy up in Vermont. And she said, ‘Well, let me read it. Top of the fold, headline, Biden, poorest man in Congress.’”
— at a March campaign event in Nevada

He continued to rank near the bottom for net worth throughout his decades-long career in the Senate. According to Mr. Biden’s tax returns, he and his wife, Jill, earned less than $400,000 almost every year from 1998 to 2016. But they earned more than $400,000 in 2013 and in every year since 2017, ranging from $408,733 in 2013 to more than $11 million in 2017. (The president’s yearly salary, under federal law, is $400,000.)

Stories too good to be true

WHAT WAS SAID

“Ambrose Finnegan — we called him Uncle Bosie — he was shot down. He was Army Air Corps before there was an Air Force. He flew single engine planes, reconnaissance flights over New Guinea. He had volunteered because someone couldn’t make it. He got shot down in an area where there were a lot of cannibals in New Guinea at the time.”
— in remarks to reporters in April

In his 2007 autobiography, Mr. Biden wrote that he often heard family lore about his hero uncle, Ambrose Finnegan Jr., who was a pilot during World War II. But his suggestion that Mr. Finnegan was shot down and cannibalized in New Guinea is not supported by military records or anthropologists.

According to the agency of the Pentagon that accounts for the missing or those taken prisoner during war, Mr. Finnegan, a second lieutenant, was a passenger on an aircraft that crashed into the ocean on the north coast of New Guinea in May 1944 after its engines failed. Three men, including Mr. Biden’s uncle, were lost in the crash while a fourth was rescued by a passing barge. There are no indications that the plane was shot down or that Mr. Finnegan was flying the plane.

Mr. Finnegan would have been an unlikely victim of cannibalism in New Guinea, anthropologists and locals told PolitiFact and The Guardian. Studies of cannibalism in the country have noted that victims tended to be enemies from warring tribes as an act of revenge or deceased relatives as part of a mourning ritual.

Mr. Biden shared his account of Mr. Finnegan’s death after visiting a war memorial in Scranton, Pa., that bore his uncle’s name. The story was meant to highlight Mr. Biden’s commitment to equipping troops and honoring veterans, the White House said.

WHAT WAS SAID

“I was getting on the train, and one of the senior guys at Amtrak — I became friends with all of them after all the years, and I’ve ridden 36 years as a senator — and he comes up to me — his name is Angelo — and he comes over and says, ‘Joey, baby!’ He grabs my cheek, and I thought they were going to shoot him. And I said, ‘Ang, what’s the matter?’ He said, ‘I just read in the newspaper’ — because they keep meticulous mileage about how many times you — how many miles you use an aircraft for the United States Air Force as vice president. ‘I just read in the paper, Joey, you traveled 1,200,000 miles on Air Force Two.’”
— in a speech in Nevada in December

This story, as told, stretches credulity. Mr. Biden logged 1.2 million miles on Air Force Two in early 2016, according to himself. Angelo Negri, the conductor, retired from Amtrak in 1993 and died in 2014. It is possible that Mr. Biden mistook another conductor for Mr. Negri: He recounted in 2009 speaking with an unnamed Amtrak employee, who also called out to him, “Joey, baby.”