He was born in St. Gallen half an hour after his twin sister. He enjoyed a carefree country childhood until the family moved to Zürich in 1949. He enrolled in the Swiss Federal Institute of Technology (ETH) in 1951, where he studied with Wolfgang Pauli. His doctoral dissertation was on his work measuring the length changes of superconductors at the magnetic-field-induced superconducting transition, a project begun by Jörgen Lykke Olsen. In the course of his research, he found that he had to do most of his research at night after the city was asleep because his measurements were so sensitive to vibration.
His studies were interrupted by his military service in the Swiss mountain infantry. In 1961, he married Rose-Marie Egger. Their honeymoon trip to the United States included a stint doing research on thermal conductivity of type-II superconductors and metals with Bernie Serin at Rutgers University in New Jersey.
In 1963, he joined the IBM Research Laboratory in Rüschlikon under the direction of Ambros Speiser. The first couple of years at IBM, he studied Kondo systems with magnetoresistance in pulsed magnetic fields. He then began studying magnetic phase diagrams, which eventually brought him into the field of critical phenomena.