Fully 17% of Holyrood's elected members were educated independently - in contrast to a Scottish national average of less than 4%. However, the Scottish Parliament remains much more democratic in its intake than Westminster, where 34% of members attended fee-paying schools.
Eton College alone produced 20 MPs, including Prime Minister David Cameron.
The same prestigious fee-paying school accounted for two MSPs, Alex Fergusson and Jamie McGrigor. A single Glasgow comprehensive, Hyndland, has three members in Holyrood.
Professor Michael Keating - the director of the Scottish Centre for Constitutional Change - has been studying the backgrounds of Scottish politics for nearly 40 years.
He said: "The figures for the number of privately educated MSPs probably represents the elite of society as a whole. You would find the same thing in business or law. These numbers do demonstrate that MSPs are not socially representative."
Conservatives are far more likely to be privately educated than representatives of other parties. Just over half of Tory MPs went to a fee-paying school; just under half of MSPs did. Their leader Ruth Davidson, went to a state comprehensive, Buckhaven High in Fife.
However, the smaller number of Conservatives in the Scottish Parliament means their privately-educated members have a limited impact on total figures for MSPs.
The share of SNP MSPs who are independently educated is far lower, at 15%, including ministers Fergus Ewing, who went to Loretto in Edinburgh, and Humza Yousaf, who attended Hutchesons' Grammar in Glasgow.
First Minster Alex Salmond and Justice Secretary Kenny MacAskill went to the same state school, Linlithgow Academy. Deputy First Minister Nicola Sturgeon went to Greenwood Academy, a comprehensive in Irvine. Labour is slightly behind with 13% of its MSPs having gone to a private school, a figure that has jumped up from just 4% in its 2003 intake but which is about the same as an equivalent number of 12% among its MPs at Westminster. Its leader Johann Lamont went to Woodside Secondary in Glasgow's west end.
The Liberal Democrats have just five MSPs - but all were educated at comprehensives. Their Westminster group - led by Westminster School's Nick Clegg - is 41% privately educated.
Both independents - former SNP MSPs Jean Urquhart and John Finnie - are state-educated, as was the late Margo MacDonald, whose death last week brought the total number of MSPs down to 128.
Presiding officer Tricia Marwick went to the St Andrew's High School state comprehensive in Kirkcaldy.
Professor Keating first studied the backgrounds of Scottish politicians for his 1975 PhD. He found that twice as many MPs had gone to Glasgow University as Edinburgh. The Herald last week found that Glasgow University accounted for one-quarter of all MSPs - a bigger share of the Scottish Parliament than Oxford and Cambridge had of Westminster.