Psychology Students - Measuring Anger

[ImNotSoGood]

I have recently been planning an experiment for my Social Psychology class and it has been smooth up to the end, in which I have to find an objective(not necessarilly absolutely so) way to measure anger.

Let me introduce you to my experiment first of all:

1. The experimenter will ask the participant to read an article about 'How Terrible America/Americans Are'.

2. Half of the participants will be asked to write a small essay by hand on a page of loose leaf reacting to the essay they just read.

3. The other half will be asked to write a small essay on the computer reacting to the essay they just read.

4. ****** This is where I am stuck. I would like to objectively measure the level of anger expressed by each of the groups. Any ideas on the best way I can do this?

I expect the participants that are writing this by hand to display more anger. It is known that body position/movement affects emotion. The motion/position of writing by hand involves clenching a pen in a fist type formation (which may prime anger), while typing on a computer involes almost a caressing motion (which may in turn prime tranquility).

The real question I am asking here is, how will I measure anger here without any real technology?