Etc. Once you have the list, let the kids choose whether they want to play charades or pictionary. If you have access to the chalkboard or whiteboard, you can use that for pictionary. If not, you'll have to remember to bring an easel or writing tablet.
If you like, award prizes to the team that has the least total time guessing. Most important, a brief explanation is required that stereotyping (assuming lots of qualities of a person just because they fall into one large category) violates God's commandments in that it steals human dignity and self-respect away from the person being stereotyped and it encourages feelings that are not loving by the person doing the stereotyping. Not all jocks, for example, are dumb, though that is the stereotype. Not all Americans are overweight and self-indulgent, though that is, sadly, also the stereotype.
Recommended reading: Rev. 5 (yes, the whole chapter, esp. 5:9).
Moody Bible Institute president Erwin Lutzer compared the Roman Catholic view of free will with a man who was drowning in a sea of sin. These are sins of this world, rather than the righteousness of God's world. Then, God throws the man a rope, he grabs it and pulls himself out of the sea of sin toward God. In other words, human beings, by making the choice to grab the rope and keep pulling until they are out of this sinful world, take part in their own salvation. (Salvation is also one of the topics in Chapter 2, so this lesson may be used there as well.)
What I did in the past was to bring in Halloween masks representing demons or sins (such as pride, envy, lust, greed, gluttony). I gave these to a number of students who had to play those demons in a little skit. Then, I gave other students masks like angels. One student plays God, and one student plays a human being in the world.
Demons taunt the human repeatedly. Several practice sessions are required to make their temptations really irresistible. Next, God throws a stick or rope into the world, and the human grabs it. Gradually, he turns away from the sins and pulls himself into a closer relationship with God.
When he gets to heaven (when he is "saved" as Baptists would view the scene), the angels sing something like the hymn "Amazing Grace" or a suitable alternative that you might choose. Be sure to bring a CD or a recording of the music and a copy of the words. Most students will not know the words, and they might not sing anyway. That's why it's important to choose your angels carefully.
As a general rule, the fancier the visuals, the better students will remember the lesson. A long white robe for God, if one is available from your choir's closet, would be perfect. Also, don't accept half-hearted acting on the part of the demons either. Most 7th-graders know the difference between good and bad, and they know how to make "bad" things very tempting.
Variation: Have a second student throw a rope in as well. This student should claim to be God, while the first student really is (playing) God. This will help to emphasize our free will to choose God despite others who tell us they are just as good.
Recommended reading: Deut. 30:19-20 or Josh. 24:15-18 or 1st Kings 18:15-22.
Human psychology says we naturally categorize people by skin color, sex, size, and age. We categorize a new person we meet within about a tenth of a second in these four ways. Age takes a little longer in some cases, but our mind decides about the other three very quickly upon seeing someone.
The important lesson, from a catechetical point of view, is not that categorizing people quickly like this is bad. Rather, what students need to understand is that everyone is equal in terms of the love our Creator has shown us all. Although I don't like to dwell on negatives, it is important to point out the differences between what we hope for and what we actually do.
Make two lists: "How adults perceive 7th graders" and "How 7th graders perceive adults." Ask for adjectives that should go in the list. Some on the first list should be loud, disrespectful, disorganized, irresponsible, sloppy, slobs, and so on. Write down all of their responses without judging for both lists.
Then, have those students who match each of the items on the first list stand up in turn. Most likely, not everyone will stand up on every item. This little activity can reveal great insight into stereotyping behavior despite our categorization.
Finally, tack onto that activity and the catechesis that follows the message that even though we are all different, we are still equal in God's eyes. He just has a different calling for each of us. But each one of us is loved just as much by God, and should be loved equally by all people.
Recommended reading: Rev. 5 (whole chapter again, esp. 5:9).