Drummer, Filf, Misery, Nail and Ripper are not typical research subjects. But Dave Snell did not study typical.

The New Zealander received a doctoral degree in psychology Thursday after writing a thesis examining the social habits of headbangers, or "bogans."

When he walked up to accept his degree, Snell got that ultimate sign of respect among metal-heads: a dean held up his fist with his pinkie and index finger extended in a devil-horn salute.

A public grant he received of nearly 100,000 New Zealand dollars ($81,000) was derided by some as an example of academic and taxpayer waste.

He said his research has been worthwhile to reveal the ways in which a marginalized group can share a common identity and community.