Americans may recall the 'threat warning level' system that came into being after the terrorist attacks on the Wall Trade Center on September 9th, 2011.

It was a color coded with 5 levels. But it never once dropped below 3 - yellow, before it was dissolved in 2011. Did anyone pay attention? Another famous example is the "Doomsday Clock", created by anti-nuclear activists to increase anxiety about nuclear weapons. Even after disarmaments and the collapse of the Soviet Union, it barely moved. We are always on the verge of Doom, according to doomsday prophets, today they just say it's because of global warming, and there are still nuclear power plants, they warn.

The reason Americans aren't all that worried about nuclear war, regardless of what anti-science activists thinking about nuclear energy, is because Americans are a 'melting pot' despite the efforts of cultural revisionists to want culture to be fragmented and not speak a common language.  A paper in the Journal of Applied Social Psychology
finds that homogenous groups are less likely to be influenced by external terrorist threat alerts.

"Among people who viewed their group to be homogeneous, external threat did not translate to higher perceived threat, and they did not influence beliefs about the legitimacy of the U.S. military intervention in Iraq," said study author Rezarta Bilali, assistant professor of psychology and social intervention at New York University.

Bilali surveyed college students to try and determine the effect of external cues of security or threat - manipulated by the researchers - on perceived threat and legitimization of the U.S.'s war in Iraq, based on a person's identification with being American and beliefs about the degree to which Americans are similar to each other. The surveys, conducted in two stages, included 147 American university students. In the first stage, participants completed questionnaires measuring their identification with their American nationalities, and whether they perceived Americans to be similar to each other or different.

A few months later, participants completed additional tasks for the study's second stage. In one task, the participants read a fake newspaper article that was manipulated to communicate either security or a threat to America. Subsequently, participants completed questionnaires to gauge their opinions on the war in Iraq and whether they agreed with the U.S.'s decision to intervene.

Bilali found that participants legitimized the U.S. military intervention in Iraq to a higher degree when they were exposed to threat cues versus when they were made to believe that the U.S. is safe from terrorism. She found that participants who saw their group to be unlike each other were more likely to perceive greater threat when exposed to external terrorist threats, and they were more likely to legitimize the U.S.'s involvement in the war in Iraq.

By contrast, individuals who viewed their group to be homogeneous - in other words, viewed Americans to be like them and similar to each other - were less likely to perceive heightened threat when they read about a terrorist threat to the U.S.

"Perceiving the group as similar to one another seems to disrupt the expected relationship between external cues of threat and subjective perceptions of threat," Bilali said. "There's some evidence that homogeneity is related to increased feelings that you can cope with a disastrous event, so these results can be interpreted by looking at the role of homogeneity in increasing the perceived ability to cope with threats toward the group."

The results shed light on the potential impact of terror warning systems and media influence on different segments of the population.

"While the study creates more questions than answers, it suggests that terror threat alerts are not affecting everyone equally," Bilali said.