Short answers, pulled from the story.
Synergy describes a situation where the combined effect of two or more entities is greater than the sum of their individual effects. The word derives from the Attic Greek synergia, from synergos meaning "working together", and was first used in English around 1600 in theological writing.
The Synergism Hypothesis, proposed by Peter Corning, argues that synergistic effects have been the primary drivers of cooperative relationships at every level of living systems, from genes to social groups. The core claim is that synergistic cooperation provides functional advantages for survival and reproduction that are favored by natural selection.
Jay Hall's laboratory studies found that effective groups actively sought out points of disagreement and encouraged conflict early in discussion, while ineffective groups rushed to consensus using averaging. His research concluded that a well-functioning group can outperform even its strongest individual member.
Negative effects include the risky shift phenomenon, where groups recommend riskier decisions than members would make individually, and groupthink. Irving Janis linked groupthink to the failure to anticipate the Japanese attack on Pearl Harbor in 1941 and the Bay of Pigs Invasion fiasco in 1961.
Walt Disney pioneered synergistic marketing in the 1930s by granting dozens of firms the right to use the Mickey Mouse character in products and advertisements. Licensed goods advertised the original media, creating a feedback loop between merchandise and film sales.
Drug synergy occurs when the combined effect of two substances exceeds what either produces alone. Examples include aspirin and caffeine providing greater pain relief together, and benzodiazepines combined with barbiturates producing dramatically enhanced effects on GABA neurotransmission through different receptor mechanisms.