Gap junctions
Strong ties
Touching cells share a channel: family, coworkers, the people you see every day. Signals here roll across the sheet as a wave.
Humanity Engine / Cell signaling
A trend is a signal.
Every cell is a person, filmed like calcium imaging: a cell lights up when it takes up the trend. Click any cell to start one there.
How to read it
Ideas spread the way cells talk.
Tissues pass signals through two kinds of contact, cells answer only above a threshold, and receptors tire. Social scientists found the same three things in how people adopt songs, habits and causes.
Tunneling nanotubes
Weak ties
Thin, long bridges to distant cells: acquaintances, media, the internet. Few of them, but they let a signal jump ahead of its own wave (Granovetter, 1973).
Receptor cooperativity
Simple vs complex contagion
Some receptors fire on one molecule, others need several at once. A joke needs one friend; a habit or a protest needs several different ones (Centola & Macy, 2007).
Desensitization
Trend fatigue
Keep stimulating a receptor and it pulls back. A cell stops expressing the trend, and with memory on it never takes it up again: the trend is old to it.
Three experiments
- 01Pick "A new habit", then push weak ties to the max. It barely speeds up: complex contagions do not travel on long ties, because one distant contact is never enough.
- 02Pick "A protest" and click a single cell. Then click three touching cells. A threshold of 3 needs a cluster to start, not a lone voice.
- 03Pick "A rumor" and turn influencers off. Without hubs the same rumor crawls; with them it lands everywhere at once.
Sources: Granovetter, The Strength of Weak Ties (1973) and Threshold Models of Collective Behavior (1978); Centola & Macy, Complex Contagions and the Weakness of Long Ties (2007); Centola, The Spread of Behavior in an Online Social Network Experiment (2010); Vosoughi, Roy & Aral, The Spread of True and False News Online (2018). The sheet is a model: one cell is one person, one tick of the clock is one day.