Spot the problem

Each sentence below is loosely derived from a different published article in social science. The source appears once the answer is revealed.

Each sentence breaks the Toulmin model in some way. Diagnose which element is the weakest link — the answer (and its source article) is revealed after a correct pick or two incorrect ones.

Because political supporters on both sides showed similar brain responses to political content, ideological extremity must be a biological trait rather than something people learn.
Which Toulmin element is the problem?
Diagnose the weakest link in the argument.
In four large studies, people who scored lower on the Cognitive Reflection Test were more likely to rate strongly politically biased fake-news headlines as accurate. This was true for headlines that favoured their own party and for headlines that favoured the other party.
Which Toulmin element is the problem?
Diagnose the weakest link in the argument.
Because tweets about gun control, same-sex marriage, and climate change that used moral-emotional words were retweeted more often than neutral ones, using such language guarantees that any political message will go viral on any platform.
Which Toulmin element is the problem?
Diagnose the weakest link in the argument.
Since political supporters tend to believe information that fits the views of their political group, it follows that they cannot think rationally at all and cannot be reached by any evidence-based intervention.
Which Toulmin element is the problem?
Diagnose the weakest link in the argument.
The claim that self-identified libertarians value individual liberty more than harm-avoidance or in-group loyalty is supported by survey data on 16 psychological measures. It is also supported by economic studies showing that countries with lower top tax rates tend to report higher subjective well-being.
Which Toulmin element is the problem?
Diagnose the weakest link in the argument.
Although decades of research show that incidental emotions — such as anger or sadness left over from an unrelated event — systematically bias judgements about probability, blame, and risk, decision-makers in finance, law, and medicine should keep assuming that emotion plays no real role in their professional reasoning.
Which Toulmin element is the problem?
Diagnose the weakest link in the argument.