Calhoun designed an ideal environment for rats, called “mouse utopia,” with abundant food, water and space, in order to study the social dynamics of a growing population.

Initially, the colony prospered, but after 317 days, population growth began to stagnate. Upon reaching 600 mice, serious social problems arose: hierarchies were established, the strongest individuals began to attack others, and aggressive and maladaptive behaviors emerged, such as violence between females and a lack of reproductive interest in males. As passive, non-reproductive (beautiful mice) males dominated, the birth rate plummeted, juvenile mortality reached 100%, and the colony collapsed into cannibalism and homosexuality.

The experiment was repeated 25 times, each time with similar results, and has been used to model the study of social collapse and urban sociology.

His truly breakthrough performance was as Eddie Adams, also known as Dirk Diggler, a porn actor, in the critically acclaimed film Boogie Nights (1997). This role significantly boosted his acting career. Wahlberg continued to build his filmography with roles in Traveller (1997), The Big Hit (1998), The Corruptor (1999), and Three Kings (1999).

Jolie committed to acting professionally at the age of 16, but initially found it difficult to pass auditions, often being told that her demeanor was “too dark.” She appeared in five of her brother’s student films, made while he attended the USC School of Cinema-Television, as well as in several music videos.

Jolie started her professional film career in 1993, when she played her first leading role in the direct-to-video science-fiction sequel Cyborg 2. She was so disappointed with the film that she did not audition again for a year. Following a supporting role in the independent film Without Evidence (1995), she starred in her first major studio film, Hackers (1995). The film failed to make a profit at the box office, but developed a cult following after its video release. The role in Hackers is considered Jolie’s breakthrough.

Jolie’s career prospects improved after she won a Golden Globe Award for her performance in TNT’s George Wallace (1997). The film was well received by critics, and Jolie received a nomination for a Primetime Emmy Award for Outstanding Supporting Actress in a Miniseries or a Movie for her performance.

Jolie portrayed supermodel Gia Carangi in HBO’s Gia (1998). The television film chronicles the destruction of Carangi’s life and career as a result of her addiction to heroin, and her decline and death from AIDS in the mid-1980s. For the second consecutive year, Jolie won a Golden Globe Award and received an Emmy Award nomination. She also won her first Screen Actors Guild Award.

Following the previously filmed gangster film Hell’s Kitchen (1998), Jolie returned to the screen in Playing by Heart (1998), part of an ensemble cast that included Sean Connery, Gillian Anderson, and Ryan Phillippe. The film received predominantly positive reviews, and Jolie was praised in particular. She won the Breakthrough Performance Award from the National Board of Review.