Flagrant abuses of power are preventing special needs services from reaching the most disadvantaged children.
Forty out of 50 educational psychologists who took part in a Scottish survey provided examples of people using rank and influence to procure resources, Tommy MacKay told the British Psychological Society conference in Brighton this week.
Mr MacKay, a lecturer in psychology at Strathclyde University, said that people with good connections were "cynically tapping into the network". He believes a statement about the equitable provision of services should be included in all local authority equal opportunities policies to help officials to withstand such pressure. Several authorities had given unreserved support for this, he said.
Mr MacKay, who received this year's BPS award for Challenging Inequality of Opportunity, also said he had examined the distribution of records of needs (statements of SEN in England and Wales) in 2,367 Scottish primary schools.
Instead of finding the expected "significant" skewing of resources towards areas of greatest socio-economic disadvantage, he found only the "slightest correlation". In fact there was no skewing at all in the top 40 and bottom 40 schools in terms of disadvantage.
He said that the needs of pupils in disadvantaged areas were so great that often it "was hard to know where to start" in opening records of need. The worst cases attracting help in schools in better-off areas might not even register in schools in very depressed areas.
Mr MacKay illustrated the type of abuse that was prevalent by referring to a phone call one psychologist had received from a senior education officer. "It was explained by the caller that he would receive a referral involving a boy who was having 'a sticky time with spelling', but who was below the level of need that would normally be viewed as the basis for taking up a referral.
"The caller had said: 'If I tell you he is the son of the council leader then you will know what level of priority we are talking about'."
Another psychologist had described a case where the "least deserving" of three children on a waiting list for special help had been successful because the parents were "wealthier, articulate and involved with the right people".