Question: What year was the leader of the Stanford marshmallow experiment born?

Context paragraphs:
John Matthias: John Matthias is an American poet.  He was born in Columbus, Ohio, in 1941.  Matthias attended the Ohio State University and Stanford University.  While still in high school, he studied with John Berryman at a summer writing conference at the University of Utah in 1959 and kept in touch with Berryman for the rest of the latter's life.  While in graduate school at Stanford he studied under the poet and critic Yvor Winters but did not conform to Winters' stringent anti-modernist position.  In fact, Matthias became deeply interested in modernism, especially British modernism, which he came to know well during many years of residence in England, editing the anthology "23 Modern British Poets" in 1970, a groundbreaking personal intervention.  His peers at Stanford included two future poets laureate of the United States, Robert Hass and Robert Pinsky, as well as the poets Ken Fields, James McMichael, and John Peck.  When he left Stanford in 1966, he spent a year in London as a Fulbright Scholar where he met Diana Adams, and married her a year later.  Diana's distinguished family includes several artists and writers, including her brother-in-law Wayland Young (Lord Kennet), the sculptor Emily Young, and the novelist Louisa Young.  Many of Matthias’s poems deal with this family.  In 1976 Matthias became a Visiting Fellow of Clare Hall, Cambridge, and has since 1977 been a Life Member.  Although his main academic job has been at the University of Notre Dame, he has spent much of his professional life in Britain, where he did major scholarly work on the Anglo-Welsh poet and painter David Jones, editing both the poetry and essays on Jones’ work for Faber and Faber, the National Poetry Foundation, and University of Wales Press.

Discos Qualiton: Discos Qualiton was a record label, published by the extinct recording studio Fonema S.A.  A garage experiment born in Rosario, Argentina in 1961, Qualiton would later become a major independent project influencing a generation of artists, writers, musicians, poets and filmmakers.

Stanford marshmallow experiment: The Stanford marshmallow experiment was a series of studies on delayed gratification in the late 1960s and early 1970s led by psychologist Walter Mischel, then a professor at Stanford University.  In these studies, a child was offered a choice between one small reward provided immediately or two small rewards (i.e., a larger later reward) if they waited for a short period, approximately 15 minutes, during which the tester left the room and then returned.  (The reward was sometimes a marshmallow, but often a cookie or a pretzel.)  In follow-up studies, the researchers found that children who were able to wait longer for the preferred rewards tended to have better life outcomes, as measured by SAT scores, educational attainment, body mass index (BMI), and other life measures.

Christian McCaffrey: Christian Jackson McCaffrey (born June 7, 1996) is an American football running back for the Carolina Panthers of the National Football League (NFL).  He played college football at Stanford, and was drafted by the Panthers with the eighth overall pick in the 2017 NFL Draft.  As a sophomore in 2015, McCaffrey was the AP College Football Player of the Year and the runner-up for the Heisman Trophy.  He holds the NCAA record for most all-purpose yards in a season with 3,864.  He is the son of former Stanford and NFL wide receiver Ed McCaffrey and former Stanford soccer star Lisa McCaffrey, who is the daughter of U.S. Olympian Dave Sime.

Philip Zimbardo: Philip George Zimbardo (born March 23, 1933) is a psychologist and a professor emeritus at Stanford University.  He became known for his 1971 Stanford prison experiment and has since authored various introductory psychology books, textbooks for college students, and other notable works, including "The Lucifer Effect", "The Time Paradox" and "The Time Cure".  He is also the founder and president of the Heroic Imagination Project.

Stanford Prison Experiment (band): Stanford Prison Experiment was an American punk band based in Los Angeles, California, whose name was a reference to the Stanford prison experiment conducted by psychologist Philip Zimbardo in 1971.  The band represented various subgenres such as hardcore, post-hardcore, and grunge.  Its leader learned about the SPE as an employee for the audio/visual dept at UCLA (He set up/played the film for a class).

Adlène Hicheur: Adlène Hicheur (born 4 December 1976) is a particle physicist with dual Algerian and French citizenship.  After his master of theoretical physics in Lyon, he joined LAPP (Laboratoire d'Annecy le Vieux de Physique des Particules) to work on the BaBar experiment, located at the Stanford Linear Accelerator Center.  His thesis, defended in 2003, was about the production of high energy Eta prime mesons in the decays of B mesons.  After that he was a Postdoctorate in England at the Rutherford Appleton Laboratory, where he worked on the ATLAS experiment at LHC.  He then joined the high energy physics department of École Polytechnique Fédérale de Lausanne (EPFL) and works currently on the LHCb experiment.

Tara VanDerveer: Tara Ann VanDerveer (born June 26, 1953) is an American basketball coach who has been the head women's basketball coach at Stanford University since 1985.  Designated the Setsuko Ishiyama Director of Women's Basketball, VanDerveer led the Stanford Cardinal to two NCAA Women's Division I Basketball Championships: in 1990 and 1992.  She stepped away from the Stanford program for a year to serve as the U.S. national team head coach at the 1996 Olympic Games.  VanDerveer is the 1990 Naismith National Coach of the Year and a ten-time Pac-12 Coach of the Year.  She is also one of only six NCAA Women's Basketball coaches to win over 900 games, and one of three NCAA Division I coaches – men's or women's – to win 1,000 games.

Elephant's toothpaste: Elephant's toothpaste is a foamy substance caused by the rapid decomposition of hydrogen peroxide.  This is often used for classroom demonstrations because it requires only a small number of ingredients and makes a "volcano of foam".  This sometimes is known as the "Marshmallow Experiment", but is unrelated to the psychological Stanford marshmallow experiment.

Walter Mischel: Walter Mischel (] ; born February 22, 1930) is an Austrian-born American psychologist specializing in personality theory and social psychology.  He is the Robert Johnston Niven Professor of Humane Letters in the Department of Psychology at Columbia University.  A "Review of General Psychology" survey, published in 2002, ranked Mischel as the 25th most cited psychologist of the 20th century.

Supporting paragraphs: Stanford marshmallow experiment Walter Mischel
Answer: 1930