Human Genetics Survey
Instructions: As a class, go over each of the following traits and determine how many in the class exhibit the phenotype.
You can also print out "Bingo" cards as a way to keep track!
Also view the presentation that shows pictures of these traits at Human Genetic Traits via docs.google.com.
Most of these traits are not entirely controlled by genetics, even the classical trait such as hitchhiker's thumb is not a simple dominant / recessive inheritance pattern.
Myths of Human Genetics by John McDonald details how many human traits we assumed are recessive (or dominant) are actually more complex, and likely controlled by multiple factors, including environmental.
I would encourage you to include a discussion of the myths with your class before doing this simple activity that surveys members of your class for a variety of potentially genetic traits.
This is also a good starter for a discussion on "nature versus nuture."