Warsaw — Apart from a weak economy, the most intractable problem for Poland's martial law authorities continues to be Polish youth. Persistent police harassment of young people, which contrasts glaringly to official calls for ''active'' engagement of young Poles in helping overcome an economic crisis, has only helped perpetuate the unease.
Public feeling at large - as well as youth's - was roused anew by an incident earlier this month in which a 19-year-old schoolboy died two days after a brush with police. Although the circumstances are not yet fully clear, it was not at all surprising that an almost automatic public presumption of police culpability drew an estimated 10,000 people to the boy's funeral in a silent, eloquent protest.
From witnesses to the events, it appears this particular tragedy may have resulted from a sequence of unfortunate misunderstandings of a kind likely to happen any place where youth's frustrations come into collision with established law and order.
But in Poland, youth - which formed so much of Solidarity's mass following - and authority are at loggerheads. A decade of intermittent conflict escalated through 1981 and the martial law year that followed. It broke out again to a lesser but still serious extent in the first three days of this month. Throughout, police behavior has often, quite unnecessarily, contributed to its aggravation.
But a sense of proportion is still needed, for street demonstrations and riots here since 1980 have, in fact, caused fewer casualties than in many countries, under martial law or not, where political conflict produces civil violence.
Figures, however, are not the issue. It is the principle of police brutality; and here in Poland, with so much else emotive of strong passions - and where more than half the nation is under 30 - it has become a transcendental issue and an increasingly bitter one.
Officials privately admit this. Many are plainly saddened by it and are acutely embarrassed when the question is raised.
The Communist Party leadership has set up its own committee for youth affairs , as one of its promised ''institutional guarantees.'' It is headed by Waldemar Swirgon, who, at 28, is still young compared with the proven older hands communist parties usually put in this kind of job.
Two recent press contributions on the subject of youth suggest the scope of the disillusionment and alienation he must deal with: (1) the findings (published by Zycie Warszawy) of a Warsaw social institute's recent probe into social attitudes among 6,000 pupils and students between 15 and 22, and (2) a Polityka interview with 12 seniors in secondary school.
Asked about their political opinions, about half of the 6,000 interviews - according to the institute's Prof. Grzegorz Nowacki - opted for ''socialism,'' though with reservations about its practice in Poland today.
But the poll also revealed a marked increase in the ''don't knows.'' When martial law was first introduced in late 1981, a similar inquiry showed only 10 percent of students uncommitted or undecided about what kind of world, or Poland , they wanted to live in. Through last year under martial law, that figured more than tripled.
The survey shows a largely disaffected student generation caught up in a deep crisis not of its own making. It portrays a generation balking at anything smacking of a return to pre-Solidarity Poland and at least ''suspicious'' of all post-Solidarity public institutions and persons.
The professor sees it as ''a sign of withdrawal into the domain of private life.''
''Students say,'' he went on, ''they wish to influence affairs through their work . . . and involvement, but they are convinced they cannot do so because of the numerous barriers in their path.''
He expressed the need for more information given to young people, and an increased dialogue with them. ''Presented with the one and only official interpretation,'' he said, ''they will reject it. It is only natural.''
Students are complaining, as they have for years, of the omissions and superficiality with which any ideologically sensitive subject is again being taught. Polityka's interviewees spoke of ''blank spots'' in history, such as the veil drawn over many aspects of Soviet-Polish relations since the 1920 war. (Wisely, after August 1980 and through 1981 there was a considerable lifting of the veil - until martial law dropped it once more.)
Now, ''Teachers pretend certain dates never happened,'' said a student. ''We still do not know what precisely happened on Sept. 17, 1939 (when the Soviet Army entered Poland as Hitler overran it from the West),'' another said.
This healthy desire to know was frequently voiced. ''We do not think the Poles have always been saints. One cannot blame all the sins of history on neighbors,'' one student said. Another added: ''Knowledge can bring nations closer together. Half-truths and falsehoods separate them.''
It is not the economic hardships for many that antagonize Polish students. They ride these cheerfully. Their resentment is directed at such teaching practices and at authority's counterproductive behavior in terms of persistent harassment of young people.
''Just being young sometimes seems to be an offense,'' said a young girl who - without reason - was bullied by the police on May Day. (''Go for the young ones,'' a police officer was heard telling his men as they moved in to break up a quite peaceful crowd.) ''They act as though we are all dropouts and lay-abouts , '' she added.
Frequently, on these tense anniversary days, one has seen quietly behaving young men on the street - giving no visible pretext whatever for it - being stopped by the police, their identity cards scrutinized, and names taken.
They don't protest. They just stand silent while it goes on. But to any thoughtful observer the look on these young faces is eloquent, expressive of the alienation and withdrawal of young people who remain unmoved by a regime's promises of a better future.