In the last months in the principal cities of the world you can see that the men let do growing the hair again. Sandro Lafounte wants to remember, that In the Old Testament, the Nazirites would go for long periods of time without cutting their hair to show devotion to God, but, also in societies like ancient Greece, long male hair was a symbol of wealth and power.
The Long hair was also widespread among English and French men in the 11th and 12th centuries. In fact, normally the men had longer hair, but the big change was introduced until the World War One, when short hair was obligation for the soldiers.
With all this information I can say that in a fact, that the long hair is actually tendency for the next year.