Robert Tucker, a psychologist and specialist in black male-female relationships, is smooth, self-assured. He's not macho or cool. Because being cool is one of the problems that has led to misunderstandings between black men and women.

"There are two kinds of black men, those who can't say 'I love you,' and those who say it very quickly and it doesn't mean anything," says Tucker, 41, who says he was trained to be cool as a teen-ager.

"Learning to say 'I love you' and mean it is hard because that's interpreted as being vulnerable. And we black have been taught to fight that, fight showing emotions. We have to hide ourselves behind being cool. Being cool will get you over and help you succeed with women."

Tucker, who along with his wife, Leota, has become a professional star in the current, hot debate over troubles between black men and women, was in Washington yesterday day for a conference on "The Black Male in America: Survival for the Future." Tucker, a Yale University professor whose avocatioin is holding workshops on black personal relationships, gave the keynote address, "How About Your Son's Mother?"

Given the real and statistical depression facing the black man -- the lowest life expectancy rate in the country, the highest unemployment rate, an unusually high infant mortality rate -- a discussion of his personal woes at a national conference might strike some as frivolous. But says Leota Tucker, "invariably, in all phases of our work we have found that black male and female relationships are an issue. And communications is the problem."

Dr. Lawrence Gary, director of Howard University's Institute for Urban Affairs and Research, the sponsoring group, said, "We don't see Tucker's work as a contradiction, but we see him as a scholar who is addressing the principal problem of survival, the survival of the black family."

Tucker told the conference, "It's hard being a black man in white America, because we are constantly operating under system-sanctioned disadvantage . . . Black male survival will be largely determined by how well we handle two major tasks, developing unity and integrity in our political life and repairing our relationship with our women." His 100 listeners in a meeting room of the Shoreham-Americana Hotel applauded.

When John, 37, and Jane, 36, first came to one of the Tuckers' workshops, they insisted they didn't have any problems. It turned out John and Jane didn't really talk to one another and only heard what they wanted to hear when they did. They competed for their daughter's affection. John insulted his wife because she was bright and had a job. Jane was totally unsatisfied with their sex life while John thought he was "raisin' hell." Now they have learned to say the positive things first, write letters to one another and even tape record their conversations.

"Just being black complicates the problems of a personal relationship," says Leota Tucker, the director of New Haven, Conn.'s, Department of Welfare.

"One common problem among black couples is that they both feel exploited. And the black men feel they are being compared unfavorably by their black women to white men," says Tucker. "And neither can express the rage that racism leaves them with every day."

Robert Tucker adds, "That was a key, they didn't see how racism was coming between them. They didn't talk it out, how it happened, what was their reaction, how did they feel six hours later. Instead it was expressed by 'I told you I hated string beans.'"

Trying to appease those psychological bruises seems to be the hardest hurdle for black couples. "We are beaten down so much. We are told we are not worthy . . . You don't want to hear that in a personal relationship," says Tucker.

His wife elaborates, "Mutual stroking is hard, even in committed relationships. And I hate to blame it on black men, but they can't say 'I love you,' and that's what women want to hear."

Jack, 42, and Jill, 35, both survivors of turbulent first marriages, were engaged but worried about the loss of freedoms another marriage would bring. Jack wanted to go out on Friday nights with the guys but objected to Jill spending the weekend with her single friends. Jack finally admitted he wanted her to be dependent, that he was jealous and suspicious she was looking for another man. Jill learned she just had to reassure him she was not rejecting him. They married.

His divorce and his remarriage got Robert Tucker into this business. "Personal relations had always been traumatic for me. I'm from a broken home, and though my mother instilled in me that a good marriage was a worthy goal, I had no role model. So I made a number of poor decisions. I had well-formed ideas of the economic and physical things, but I couldn't express the emotional," says Tucker.

After 12 years of marriage, two children, and several career changes from teaching -- working in consumer education for a poverty program, earning a masters in urban affairs, working with drug addicts -- Tucker decided the relationship wasn't viable.

"It was during my work with the drug addicts that I realized I wasn't in touch with myself. And in working with them I owned up to my own needs, the need to be loved," says Tucker.

"But getting a divorce was very hard. The need to do it was in my head but the other part of me wanted the permanence, acknowledged the responsibility. The breaking point was acknowledging that I was teaching things I wasn't applying in my own life."

During this period of reawakening, Tucker met Leota Tucker, a psychology graduate student, who had grown up in the same town, New Haven. She had experienced an early marriage, had one child and had finished the divorce process.

"For me the issue was my independence.I had been divorced almost seven years. It was also the issue of being able to share my apartment, the ability to love. There was no issue over his desirability. But can I share my space?" says Leota Tucker. They found their research was compatible. And treir private chemistry made their "Black Love Workshops" exciting. "They were powerful," says Tucker, "and we were the models for behavior. There we were, walking the walk and talking the talk."

At home, says Leota Tucker, their 4 1/2-year relationship is "good." Tucker amends that to "very good."

And she explains, "He has encouraged me to take risks, to help overcome my shyness, he taught me how to fight and to articulate anger."

He says, "The sulking part, now I did more of that."

She adds, "Well, three days was really ridiculous."

And Robert Tucker has the last word, on his own relationship, and issues a warning to others, "I have learned to tell her I love her even though I am mad." CAPTION: Picture, Robert Tucker, by Harry Naltchayan; Illustration, no caption, by Heather Taylor, Copyright (c) 1978, Courtesy Essence Communications, Inc.