Marshall Segall, a beloved mentor, esteemed cross-cultural psychologist and fiercely engaged humanitarian, died on Dec. 20. He was 95.

Marshall was born on April 22, 1930. He will be remembered by friends and colleagues as a man who lived his life with gusto and an unshakable positive disposition. He was regarded as an excellent teacher and “the best boss” one could ever have, a person who was “full of fun, wise in dealing with difficult people, a teacher through and through.”

Together with his late wife, Sally, they were a “font of hospitality and thoughtful conversations,” creating warm homes in places like Syracuse and Martha’s Vineyard and during their tours abroad in Florence, Strasbourg and London. His energy was infectious, making others feel they “could do more than I might have once thought,” and many credit him with changing the direction of their lives, “not only intellectually, but also in terms of what it means to live a good life.”

His professional life was defined by his pioneering work in cross-cultural psychology and his commitment to addressing significant social issues. He authored or co-authored books on cross-cultural psychology while at Syracuse University in conjunction with his work in Africa and Europe. He believed that cross-cultural psychology should have relevance to current affairs and public policy; one of his major early interests was the cultural versus biological origins of aggression.

In his later career, Marshall focused almost completely on combating racism. His final major accomplishment was the translation and distribution of the exhibit, All of Us Are Related, Each of Us is Unique, based on research demonstrating that race is not a biological concept but a sociological construct. He believed this finding should be widely publicized in the United States, and he regularly gave opening speeches for the exhibit.

A man of varied interests, Marshall was active in local theatre and singing groups during his high school and college years, a passion for music that remained a great source of joy until his death.

He developed a love for Europe as a student in Geneva, and that continued throughout his life as he lived, worked and developed lasting friendships in England, France, Switzerland and Italy. While there, he would never pass up a good meal or a trip to the theatre or art museum, keen to enjoy everything that was on offer.

In retirement, Marshall and Sally moved to Martha’s Vineyard and lived there for a decade. Marshall became a keen fisherman, teaming up for the Martha’s Vineyard Striped Bass and Bluefish Derby, and an artist who took up painting watercolors and later oils. He sold his paintings of local sites and Paris highlights as cards under the signature Marshall Arts. He also always enjoyed playing the odds, whether it was poker, the stock market, the horses or the lottery.

Over 60 years together, Marshall and Sally shared adventures and a love of travel, opening their home to friends and family. They were never happier than when they were entertaining or enjoying a meal with those closest to them.

Marshall was diagnosed with dementia roughly 10 years ago. Despite the progression of his illness, he remained in good humor, retaining his wit and social skills. He continued to paint, sing, and enjoy going out and people watching, taking pictures, and commenting on the beauty of the natural world. To the very end, he never met a bowl of ice cream that he didn’t think was extraordinary.

Marshall is survived by a sister-in-law, Janine Moden, two daughters, BK Segall and Laura Moore, two stepchildren, Diane Block and Edward Wilson, and grandchildren Noah Block, Claire and Christopher Wilson, and Ryan Segall.

The family will hold a private memorial service for Marshall.