The actions of the Spanish government reveal a deep misunderstanding about the psychology of the independence movement. Authorities are attempting to wear down the movement by denying a vote. Our findings suggested that Madrid’s current approach may well backfire: The government’s muscular response to Catalans’ desire for self-determination could increase the number of independentists and heighten their passion, which, in the long run, may further erode the stability and reputation of Spain’s central government. Allowing a vote to proceed, meanwhile, could actually strengthen Madrid.

The current strain of the Catalan independence movement began under the rule of fascist dictator Francisco Franco, who took over Spain in 1939. Under Franco, the public use of the Catalan language was banned, and all specifically Catalan institutions, such as the Government of Catalonia, were abolished as part of an attempt to end regionalism in Spain. Shortly after Franco’s death in 1975, the government reinstated Catalonia’s status as an autonomous community within Spain. But a small minority of activists still wanted full independence.

The share of those favoring independence began to rise steeply in 2010, from 25 percent to its peak of 57 percent in 2012. The first reason for this rise was likely the 2008 economic crisis. Using government data from 2005 to 2016, we found a very high correlation between support for independence and unemployment in Catalonia. The second reason for this rise was public outrage at the 2010 constitutional court’s cutting down of reforms aimed at increasing sovereignty in Catalonia’s Statute of Autonomy, its equivalent of a constitution. Both events led many to feel that Catalonia would be better off under self rule. Since then, Madrid has been adamantly opposed to an independence referendum, arguing that it is illegal according to the 1978 Spanish constitution (which mentions the “indissoluble unity of the Spanish Nation”).

Since then, the Catalan independence movement has been building. It is driven by strong personal identification with Catalan culture and what social psychologists call sacred values: moral values of the highest significance that, in some cases, people would give their lives for.

According to our research, the top two sacred values motivating the Catalan movement were the right to vote for independence and the protection of Catalan identity. In studies of conflicts around the world, our colleagues have found that threats to sacred values and identities often lead to increased activism and, sometimes, violence. The denial of a vote is a threat to these values and identity and, most likely, will only further fuel the independence movement. Until recently, many supporters of the referendum have been undecided on the question of independence. However, the denial of the vote by Madrid has outraged some, turning them into pro-independence activists.