Notable contributors were Joseph Wolpe in South Africa,
M.B. Shipiro and Hans Eysenck in Britain,
and John B. Watson and B.F. Skinner in the United States.
As early as 1952, in one of the earliest studies of psychotherapy treatment,
Hans Eysenck reported that two thirds of therapy patients improved significantly
or recovered on their own within two years, whether or not they received psychotherapy.
As early as 1952, in one of the earliest studies of psychotherapy treatment,
Hans Eysenck reported that two thirds of therapy patients improved significantly
or recovered on their own within two years, whether or not they received psychotherapy. cite book |last=Eysenck |first=Hans |year=1952 |title=The Effects of Psychotherapy:.