The long-awaited research - commissioned two years ago amid major concerns about how officers were using the procedure - warned stop and search “has been used disproportionately, particularly on children and young people”.
It revealed younger people feel victimised with many having very negative views of police, how people in Glasgow were far more likely to be stopped than anywhere else and how the majority of searches found nothing.
The report says: “There continue to be many examples of where the practice is being undertaken in ways which are not acceptable, nor having the impact that is intended.”
The Scottish Police Authority commissioned report found an above average number of teenagers are being stopped the most despite being the least likely to be found with anything - while people in their late 20s are targeted the least despite being the most likely to be carrying something.
Edinburgh University research for the SPA found children from mainstream school were twice as likely to be searched compared to those at private schools, yet offending rates for both are virtually the same.
Of more than 1,000 12-to-16 year olds questioned, 23 per cent said they had been stopped and searched at least once by the police in the last year. Many said they were “scared” or “embarrassed” and a number said they had no idea why they had been searched.
The report says: “The widespread and frequent use of stop and search appears to have cast an excessively wide net over children in Glasgow and Edinburgh, leading to high levels of unjustified and intrusive police contact. “
Overall, 13% of stop and search encounters in that age group resulted in detection, with the report saying: “It is clear many children were stopped and
searched, without good reason or explanation.”
A separate report, also commissioned by the SPA, also raised concerns about “the grounds used to justify stop and search being unclear, unreasonable, not based on sufficient evidence, and sometimes not communicated at all.”
It added: “Improvements need to be made to both the way in which stops and searches are conducted and in the way police engage more widely with the affected communities.
The research will be used as part of a consultations by the Scottish Government on a draft Code of Practice for Stop and Search and Police Powers to search children and young people.
John Foley, Chief Executive of the SPA said: “The findings are consistent with public concerns raised three years ago.
“The SPA has shared this research with Police Scotland and we will work with them to ensure it continues to inform improvements in stop and search going forward.”
Last year it was announced Police Scotland will stop carrying out non-statutory, ie: voluntary, stop-and-searches of adults and children,
It came after the Scottish government asked John Scott QC to examine the controversial practice and his report found ending the searches would not prevent officers carrying out their duties effectively.
The new statutory code of practice is being introduced to underpin how stop and search is used in Scotland and a consultation is examining whether the police should have the power to search children under 18 for alcohol.
Minister for Community Safety Annabelle Ewing said: “This research published meets the SPA’s commitment to consider the long-term impact on young people and communities across Scotland and complements current Scottish Government consultations on a Code of Practice for Stop and Search and on police powers to search young people.”