In 1956 he worked on the Rembrandt commemorative exhibition in the Rijks, where certain paintings were on show which hadn't been back to Amsterdam for decades, such as the pendant portraits of Maerten Soolmans and Oopjen Coppit.
The next year, in 1969 Gerson published an update of Abraham Bredius' 1935 catalog of 611 Rembrandt paintings with his attributions based on connoiseurship.
Team member Ernst van de Wetering advocated a different approach based on a holistic study of the paintings, dismissing the age-old ideas of connoisseurship that were seen as being so controversial in favor of using non-controversial forensic techniques as well as archival research and provenance records.
In 1982 he published The Golden Age: Dutch Painters of the Seventeenth Century, which was equally as well-received as his first book on Rembrandt and earned him the Karel van Mander prize in 1985.
His father was a footballer in the Netherlands national team, and a record high jumper and both parents were teachers at the Montesorri school in Amsterdam.