What was going on when I was born?

DONALD NEVINS, who majored in history at the College of Staten Island, has left behind Caesar and Charlemagne and gone on to work as a broker on the floor of the New York Stock Exchange, where an understanding of the causes of the Peloponnesian War probably never earned anyone an extra buck. While Mr. Nevins, a 1977 graduate, did not study history with the intention of trading General Motors shares, he says there is no reason why liberal arts majors should not be able to succeed in the marketplace. Not all corporate recruiters seem to endorse Mr. Nevins's hypothesis. Liberal arts majors, particularly those in the humanities, have grown accustomed in recent years to being rebuffed by business and industry, though a few graduates like Mr. Nevins have been fortunate enough to get jobs in fields that have no outward relationship to their undergraduate studies.

The Securities and Exchange Commission announced today that it had censured one of the nation's largest accounting firms, Arthur Andersen & Company, in an administrative proceeding for numerous alleged deficiencies in the firm's audits of two public corporations, Mattel Inc. and Geon Industries. At the same time, in a separate matter, the S.E.C. released copies of unusual correspondence between the firm and the commission's enforcement division concerning a request by the commission that Arthur Andersen explain how it would handle various questionable payments by American companies involved in foreign business. Arthur Andersen consented to the order of censure while neither admitting nor denying the alleged accounting deficiencies, which involve financial statements in the early 1970's.

The United States Supreme Court agreed yesterday to review a lowercourt ruling that employees of the state-owned Long Island Rail Road were subject to New York State's Taylor Law, which bans strikes by public employees. The outcome of the court review could have a significant bearing on contract negotiations next winter between the Metropolitan Transportation Authority and the 17 unions now representing the railroad's employees. It could also affect the willingness of the authority to operate the Conrail commuter lines in Westchester County. The Reagan Administration has proposed that the authority and local agencies in other states operate such Conrail lines.

Eugene V. Rostow, President Reagan's nominee to head the Arms Control and Disarmament Agency, said today that the Reagan Administration would probably not be able to begin formal negotiations with the Soviet Union to limit strategic weapons until March 1982. ''It may be that a brilliant light will strike our officials,'' said Mr. Rostow, defending the timetable in his confirmation Excerpts from statement, page 6. hearings before the Senate Foreign Relations Committee. ''But I don't know anyone who knows what it is yet that we want to negotiate about.''

The people who listen to E.F. Hutton talk may soon be hearing some new sounds, as the Wall Street firm jumps from the brokerage business into lending. The springboard for the new thrust is a credit company, now called the E.F. Hutton Credit Corporation, acquired in May from the International Paper Company for $55 million. The credit company, which last year had $440 million in receivables, leases everything from computers and machine tools to railroad cars and airplanes. And Hutton thinks that some day it could move into consumer lending as well. ''The idea is to provide money to people rather than just taking it from them for investment,'' said Robert Fomon, Hutton's chairman. ''It is a logical additional form of financial service.''

Mark David Chapman pleaded guilty yesterday to killing John Lennon last December outside the apartment building in which the 40-year-old former Beatle lived. Ordinarily, a defendant who pleads guilty to murder faces a maximum sentence of 25 years to life. However, in return for Mr. Chapman's plea in State Supreme Court in Manhattan - a plea made against his lawyers' advice in a closed courtroom proceeding - Acting Justice Dennis Edwards Jr. promised that the sentence would not exceed 20 years to life imprisonment. Mr. Chapman will be sentenced on Aug. 24. The charge that Mr. Chapman shot Mr. Lennon to death just before 11 P.M. last Dec. 8 as the musician and his wife, Yoko Ono, returned from a recording session, had been undisputed as the lawyers assembled in court yesterday morning.

The plight of the casino gambling industry here is on display almost every night. Midnight should be a time of bustling activity at casinos like the Sands. But even some of the popular blackjack tables are vacant, except for dealers idly fingering cards, and several of the dice tables are roped off, unattended. Rows of slot machines fail to lure a single customer. In a cocktail lounge, a Las Vegas-style rock group - men in ruffled shirts accompanied by a female vocalist clad in a revealing jumpsuit - plays to an audience of mostly empty seats. Three years after the first casino opened, Atlantic City is still waiting for the payoff. Most of the city's casinos lost money in the first quarter of 1981, and executives expect profits to be scant through the year. Several companies that once seemed eager to build casinos here have postponed or canceled their plans.

A nationwide strike of air traffic controllers was averted when the Government and the union agreed on a tentative contract less than three hours before the walkout was set to begin. (Page A1.) Airlines lost passenger traffic as a result of the strike threat. Many reservations were canceled. (A19.) Inflation has fallen below 10 percent, said Murray L. Weidenbaum, chairman of the Council of Economic Advisers. Nevertheless, he added that it was unlikely that increases in the Consumer Price Index would continue to be as small as those of March and April. (D1.)

AS the sun shone from its northernmost point Sunday, bringing the summer solstice - and the longest day of the year - to the Northern Hemisphere, a mysterious hormone that may influence fertility, mood and many other body functions should have reached its annual low point in the blood of those who spent the day outdoors, according to a new finding that may ultimately revolutionize studies of the effects of light on people. Thanks to the interplay between sunlight and this hormone, the research suggests, Sunday may have been the happiest day of the year for peoples living north of the equator. The hormone, melatonin, is released from a tiny gland in the brain, called the pineal gland, at night. In some birds and reptiles, this gland is exposed on the top of the head and acts as a ''third eye,'' sending messages about light levels to the brain. The new studies, by Dr. Alfred Lewy, a research psychiatrist, show that exposure to very bright light, such as daylight, can turn off production of melatonin in people.

''When I was a kid, growing up in New York in the 40's, we would never go through a red light because we believed there was a cop behind every bush.

Alarmed by a recent increase in the number of pedestrians killed by automobiles on New York City streets, officials are trying to devise ways to combat what they say is a major contributing factor - motorists who ignore traffic signals. ''There is a sense that people are violating with impunity the traffic regulations in this city, going through red lights and passing stop signs,'' said Robert J. McGuire, the Police Commissioner. ''We see an increase in traffic fatalities, pedestrian fatalities.'' Councilman Henry J. Stern, a Manhattan Liberal who recently completed a study of red-light violations, said: ''It started out with people going through the yellow light, then it went to right turns on red. Now you have cases where people just look both ways and run the light.''

Prime Minister Menachem Begin was reported today to have told a parliamentary committee that the United States had provided him with a document expressing American concern that Iraq was planning to use its French-built reactor to manufacture nuclear weapons. The document, based on American intelligence reports, was given to Mr. Begin in January by the United States Ambassador to Israel, Samuel W. Lewis, according to an informed Israeli official. In Washington, a State Department official said that information on the Iraqi nuclear program had been exchanged at various times with Israel and other Middle East countries, but the official would not comment on the report that Ambassador Lewis had given Mr. Begin a document expressing concern about Iraq's intentions.