Feigning anger is an unwise tactic
A new study by Campagna et al. (2015) tested whether feigning anger in negotiations works. Their finding was that it did not. It generated little tactical benefit - it hardly helped to convince people right there and then - while it did generate a strategic disadvantage. This disadvantage was that it created an action-reaction cycle resulting in real anger and that it undermined mutual trust.
Feigning anger appears to be an unwise strategy. In the short term, it hardly works. In the longer term - which is relevant for the many situations in life in which ongoing relationships with people, not just single interactions - it is likely to be harmful. I think these findings are not only relevant for negotiation but also for other situations in which you try to influence people.