Are men most attractive clean shaven, with a 5'o'clock shadow, after a few days razor-free or with a full lumberjack beard?

Australian researchers took photographs of 10 men when they were clean shaven, at five and 10 days razor free and with a full beard, Medical Daily reported.

They then asked 351 women and 177 heterosexual men what they thought of the gents in various phases of beard growth. Each face was rated for attractiveness, masculinity, health and potential parenting ability.

Women picked men with 10-days of facial fuzz as the most attractive, the study revealed.

Both male and female participants chose guys with full beards having the best perceived parenting skills. Men with a little light stubble after fives days of growth got the lowest scores from both men in women in all categories.

Researchers from the University of NSW found highly fertile ladies increased their score of men's masculinity rating compared to women not ovulating.

However, the phase of fertility that women were in had no effect on their impression of a man's attractiveness.

Researchers concluded heavy facial hair conveys maturity and manliness, with less aggressiveness implied by a full beard.

The study was published in the journal Evolution and Human Behavior.

- www.nzherald.co.nz