What was going on when I was born?

Just before dawn today, Susan Jezile, like other squatters outside this city, rose early from her bed and tore down the shelter of black plastic and brushwood that had been her home, exposing her sleeping children to the wintry winds of the Cape of Good Hope. She did so, she said, because she knew that if she did not dismantle her 10-foot-square igloo of a dwelling, the authorities would demolish it and confiscate the precious materials she needs to rebuild it when they depart. So, she said, she pre-empted them to insure they had nothing to pull down. A few hours later, officials from the Western Cape Development Board did indeed arrive with crowbars and tear- gas launchers and rubber-bullet guns to demolish some houses at the squatter camp known as Phase Two. Then they left, and Mrs. Jezile rebuilt her home and sheltered her children.

A shift on aid to El Salvador has been occurring among members of Congress since the May election of Jose Napoleon Duarte as the Salvadoran President. Representative Clarence D. Long, the Maryland Democrat who is chairman of a House subcommittee that exerts major influence over foreign aid spending, said he was now prepared to approve almost all the military and economic assistance sought by the Reagan Administration for El Salvador next year. (Page A1, Column 6.) Americans' success in the Games of the XXIII Olympiad continued with two more gold medals in swimming and one in shooting. In swimming, Mary Wayte of Mercer Island, Wash., won the women's 200-meter freestyle, and the men's 800-meter freestyle relay team captured a spectacular final from West Germany by four- hundredths of a second, or no more than 3 inches. World records were broken in the three men's finals. In shooting, the American gold medal came from Ed Etzel, of Morgantown, W. Va., who won the small-bore rifle competition with a near-perfect score of 599. Michael Gross of West Germany won the 100-meter butterfly by a foot from the favored Pablo Morales of Santa Clara, Calif. (A1:1-3.)

Five young bridge players from the Boston area, suspected of cheating by using illegal signals, have been suspended from competition by the American Contract Bridge League. They face a highly unusual hearing at which videotapes of their play are to be shown. The suspensions followed the national championships in Washington, where the team members were videotaped during play. They were subsequently shown the tapes and then withdrew from the tournament.

An article yesterday on the Bayreuth Festival misidentified the first black to sing there. It was the soprano Grace Bumbry - in 1961 in ''Tannh"auser'' - and not Simon Estes.

''New York City deserves to have the tallest and greatest building in the world and I would be very interested in doing it.'' - Donald Trump. (B1:1.)

A picture caption in Metropolitan Report yesterday with an article about volunteers working at hospitals where some employees are on strike misidentified the place where one volunteer, Ben Saldanha, was working. It was the emergency room of Beth Israel Medical Center.

William M. Isaac, the chairman of the Federal Deposit Insurance Corporation, indicated today that the agency might consider raising the insurance premiums paid by banks next year to replenish the agency's reserves in the wake of help to the Continental Illinois National Bank and Trust company. Mr. Isaac, responding through a spokesman to an inquiry, said there would be no rise this year in the premiums paid by 14,000 insured commercial and savings banks. As early as possible in 1985, the spokesman said, the agency will assess ''any potential losses'' to the agency's reserves. The spokesman refused to discuss how the use of $2.5 billion of the the agency's funds to help keep the Chicago bank open might influence the agency's decision on insurance assessments, as the payment by the banks is called. Of that sum, $1.5 billion was lent in May and another $1 billion was pledged last week.

INTELLIGENCE as measured by I.Q. tests appears to be related to success in school, but it seems to have surprisingly little to do with achievement in careers, according to a growing number of psychologists. Their research has repeatedly shown that, although the best executives almost always do at least moderately well on I.Q. tests, their ranking on these tests is simply not the factor that distinguishes those who advance from those who do not. And yet successful career people clearly do a lot of thinking on their way to the pinnacle and once they get there. This seeming paradox has impelled these psychologists to abandon the kind of intelligence I.Q. tests measure and search for something else. Some describe what they are seeking as a measure of ''practical intelligence.''

When the Lotus Development Corporation received a report from an informant that Rixon Inc. had made unauthorized copies of a Lotus financial spreadsheet computer program for use in its branch offices, Lotus filed a $10 million copyright complaint. Rixon promptly settled for an undisclosed sum. In the Rixon case, as well as a new lawsuit filed last week against Health Group Inc. of Nashville, Lotus has been testing a new tactic in its campaign against the growing problem of software piracy: deterrence through fear of exposure in the courts. For years companies have been looking for ways to keep people from making unauthorized copies of computer programs, which can be worth hundreds of dollars each and which can be duplicated in a minute or so, more easily than a cassette tape. But no sooner is a new protection device found than a new method of circumventing it seems to be found, too.

Citing ''overwhelming'' evidence that lead in gasoline is a serious threat to human health, the Environmental Protection Agency today formally proposed new rules requiring that the maximum lead content of gasoline be reduced 91 percent by Jan. 1, 1986. The agency said it was also considering a total ban on lead in gasoline starting in 1995, but the Office of Management and Budget has said that more evidence is needed to support a flat prohibition on lead in gas. Therefore, a second option being considered by the E.P.A. is allowing a small quantity of lead in gas indefinitely. William D. Ruckelshaus, Administrator of the environmental agency, said today that in either case his agency's intention was total elimination of leaded gasoline by the mid-1990's.

The St. Regis Corporation and the Champion International Corporation, two of the nation's leading forest products companies, are expected to announce merger plans today, sources close to both companies said last night. The more than $2 billion merger, which would create the nation's largest producer of paper and forest products, is understood to have been approved by directors yesterday even as Rupert Murdoch, the Australian- born publisher, was proposing two separate offers to buy control of St. Regis. Responding to widespread rumors that a deal might be in the works, St. Regis stock jumped $4.50 on the New York Stock Exchange, to $50.25. It was the second most active issue of the session, with some 1.9 million shares changing hands. Champion ended the day unchanged at $19.125.

The chairman of a House subcommittee that exerts major influence over foreign aid spending said today that he was now prepared to approve almost all the military and economic assistance sought by the Reagan Administration for El Salvador next year. The decision by the chairman, Representative Clarence D. Long, seemed to indicate a significant shift in Congressional sentiment since the election of Jose Napoleon Duarte as President of El Salvador in May. In the past, Mr. Long and the panel he heads, the House Appropriations Subcommittee on Foreign Operations, have made deep cuts in foreign aid levels for El Salvador. Their actions have generally been accepted by Congress and have been central to the longstanding dispute between the White House and Congress over American policy in El Salvador.