HACKENSACK, N.J. (AP) _ A woman seeking custody of the baby she bore under a surrogate contract is an awkward parent and has a mixed-personality disorder, a psychiatrist has testified.

Marshall Schechter, professor emeritus at the University of Pennsylvania School of Medicine, said today that Mary Beth Whitehead has a personality disorder shown by paranoia, narcissism and histrionics.

Among the reasons he cited to support his view that Mrs. Whitehead is narcissistic is that she dyes her white hair brown.

''We discovered that Mrs. Whitehead was indeed Mrs. white head,'' he said. He also said that the surrogate tends to portray herself as a victim, taking little responsibility for her own actions.

Schechter, a psychiatrist for 39 years, said Monday that Mrs. Whitehead improperly held and made incorrect observations of the needs of the 11-month- old girl at the center of the unprecedented custody dispute.

He said the baby's father, William Stern, with whose sperm Mrs. Whitehead was artificially inseminated, and Stern's wife Elizabeth were adept at handling the child and knew what the baby wanted.

Schechter, one of three expert witnesses hired by the baby's court- appointed guardian, Lorraine Abraham, has recommended in court papers that the child be raised by the Sterns and that Mrs. Whitehead be denied visitation for the time being.

Superior Court Judge Harvey R. Sorkow, who is hearing the case without a jury, must decide which couple will get custody and whether the surrogate contract is valid.

Schechter watched Mrs. Whitehead and her family play with the child in the Whitehead home during a five-hour visit Jan. 10. It was the first time the baby had been in the home since she was put in the temporary custody of the Sterns in late July.

Since then, Mrs. Whitehead has visited the child twice a week, two hours each time, under supervision.

Schechter discounted the notions that Mrs. Whitehead acted as she did because she was uncomfortable about being observed or because she was unaccustomed to the child being in the house.

''This was not just the situational tension,'' he said. ''Again and again, she misrepresented what was going on in the child's mind.''

The psychiatrist said Mrs. Whitehead could not tell when the baby was tired, hungry or thirsty, or whether the baby wanted her.

For example, Schechter said, at one point Mrs. Whitehead put the baby on her lap and offered her a cup of tea, which the baby pushed away, but Mrs. Whitehead persisted to offer it.

''The baby didn't want to have it,'' he said.

At another time, Mrs. Whitehead improperly held the child, he said. Later, she didn't correctly play patty-cake with the baby.

She started to play patty-cake, and when the baby finally responded, Mrs. Whitehead said ''hooray'' and stopped playing, Schechter said.

Schechter said that the Whiteheads also didn't have the correct toys for the girl, then 9 months old, to play with.

The Sterns, meanwhile, were described in favorable terms in their actions with the baby.

Schechter said the child was especially attached to William Stern and that there was ''a great deal of smiling, cooing and verbalization in the presence of her father.''

He said Mrs. Stern, a pediatrician, properly fed and played with the child.

Earlier Monday, a psychologist testified that because the child will have to face the circumstances of her birth, Mrs. Whitehead's mental state should be weighed carefully in deciding whether she should get visitation rights.

David Brodzinsky, a Rutgers University professor, said Mrs. Whitehead has ''no diagnosable condition,'' but that because of the unusualness of the case he would recommend she not get custody and not be allowed to visit her daughter.