Many people don't realize it, but they are being exploited by a psychosocial phenomenon that is encouraging them to think irrationally. Everyone is susceptible, and it can lure you to betray your principles in order to support ideological causes. The general form of this phenomenon as defined here is called "teamism." "Ideological teamism" is a more specific manifestation. In both cases, your belonging to a team will influence what you want to believe, and can corrupt your judgment. To illustrate teamism, here are two familiar examples of how wanting to believe something will induce non-critical thinking.
First, consider a sporting event where a referee makes an incredibly close call in the final championship game. The referee's call is made within a cloud of dust, and he is the only one with a clear view of the critical event. The fans from the losing team instantly become furious and hostile. Rumors of a bad call are believed without any factual basis. Fans from the winning team instantly accept the referee's call. Neither side has any objective basis for having a strong opinion. Anger ensues, followed by fights between fans of opposing teams, and the stadium eventually erupts into rioting.
The second example illustrates an effect of ideological teamism. For this phenomenon, consider a close presidential election in which the deciding state was a statistical tie. One candidate sues, and eventually, one candidate is confirmed as the winner after a court's decision is made on procedures. Supporters of the losing candidate are furious and hostile. It takes little effort to convince them that the judge made a bad call and robbed them of the election. Rumors of fraud, corruption, incompetence, and unfairness are easily accepted and believed without any factual basis. Supporters of the winning candidate immediately defend the judge's ruling without understanding the basis of the ruling. People are outraged all over the country and neighbors become hostile with each other.
As humans, we seem to have a tendency to identify with a team and to be defensive about other perceived teams. Some have proposed that this is an inherent evolutionary trait based on tribal identity or psychology of hunter-gatherer bands. An experiment in the 1950's with fifth grade boys had interesting, yet somewhat disturbing findings. For this experiment (Robber's Cave Experiment), 22 boys were divided into two groups at the Robber's Cave State Park in Oklahoma. Initially, the groups were kept separately. As soon as the two groups became aware of each other, they immediately became defensive about territory, and were eager to challenge the other team. A set of competitive games were setup, and the hostilities between the groups escalated to alarming levels, including name calling, vandalism, and likely violence if the adult researchers (posing as staffers) hadn't prevented it. While many manifestations of teamism can lead to a harmless, exciting, and productive competition in sports and business, its corrupting influence on our judgment can have a detrimental effect on society when it affects other areas, such as science, economics, politics, and history. Our tendency to become emotionally attached to issues and ideologies encourages a loss of rationality by making us want to believe conclusions which support our ideology. People tend to rationalize what they want to believe by seeking out information that confirms what they want to believe and by ignoring contradictory information. It's unfortunate that expert economists and politicians can't agree on lessons learned from the Great Depression. Political beliefs affect economic beliefs, and two teams looking at the same data will emotionally defend opposite conclusions. On one team, FDR's policies were necessary and beneficial. On another team, FDR's policies made the Great Depression worse and longer that it needed to be. Polite intellectual disagreements are understandable, but an internet search using the words "Krugman" and "Shlaes" reveals an abundance of emotional vitriol. The quest to determine man's role in global warming is another important field which has been corrupted by ideological teamism. Ad hominem and nasty rhetoric are rampant among both researchers as well as non-scientist advocates on both sides of the issue.
What to watch for:
As with many hazards in life, recognizing the hazard is often the key to prevention. This can be useful in identifying ideological teamism in you, as well as in other people. Here are some traits that are often found in ideological teamism:
1. Emotional Attachment: It's very hard to remain objective when you are emotional about an issue. An emotional influence will encourage you to want to believe certain things. It's not wrong to be emotional about an issue, but be aware that your objectivity may be compromised.
2. Emphasis on beating the other side: When winning a debate is more important than understanding both sides of the issue, then a person has definitely crossed the line into teamism. The issue has turned into an "us against them" game. In a truly objective investigation, a person should embrace and invite viewpoints that oppose his current beliefs about a subject. A good scientist will test his own theories harshly and thoroughly in order to try to prove them wrong. An ideological teamist will use rhetorical tricks to try to deflect arguments that do not support his ideology. An ideology should win on its own merits, and not by the skill of the debater.
3. Ridicule and Insults Become Acceptable: This is a common type of ad hominem attack for the ideological team member. Normally nice people can become rude while under the influence of teamism. While it is more common to directly insult and ridicule someone else's ideology in a semi-anonymous internet forum, ridicule in a face-to-face situation most often occurs among friendly team members of the same team. Have you ever ridiculed a political issue to a friend who agrees with your politics? If so, then this may reveal an emotional attachment to an issue. Sometimes, ridiculous things happen. However, be cautious of your objectivity about an issue when you recognize it.
4. Vilification: There is a moral superiority in being a victim. I'm not just right, but my team is "better" than yours. The other side isn't just wrong; they are stupid, negligent, uncaring, irresponsible, or evil. This is standard practice in many political discussions. Godwin's Law is demonstrated over and over again in internet forums. The words "ilk" and "minions" become more common when they describe the opposition. Try an internet search of the words "Cheney" + "Ilk" or "Democrats" + "Ilk". Be cautious if you begin to feel that those with whom you disagree have ill intent. It may be that one or both of you are simply misguided.
What's in it for me?
By recognizing and preventing an emotional attachment to your ideologies, you may be less defensive and more rational in your thought processes. You'll be better able to test your beliefs and be less defensive about them. For the issues which you are right about, you will be better able to test them and discuss them calmly. For issues which you are wrong about, you'll be better able to see and accept a correction. There's nothing illogical about having strong opinions, but it's good to not get too emotionally attached to them.