Per Henrik Nils Sjöbring (9 July 1879 - 19 February 1956) was a Swedish physician and professor of psychiatry.Sjöbring was born in Aringsås, Sweden.
He received his doctorate in 1913 at Uppsala University and was a professor of psychiatry at the University of Lund 1930-1944.
He has become best known for his variables for description of personality types.
His so-called constitution factors (known as Sjöbring's theory of constitution) are called:
capacity (intelligence)
validity (psychic energy)
stability (balance in keynote)
solidity (firmness, tardiness, tenacity)By means of these variables, all people can be categorized as either normal, super- or sub-; for instance subcapable (unintelligent), subvalid (lack of psychic energy), normosolid, superstable, and so on.