Written by Kelly A. Hogan, University of North Carolina at Chapel Hill
– To practice the scientific method, beginning with an observation
– To appreciate that there are multiple ways to test a single hypothesis
Activity Description: Students are given information about females being better at articulation than males. They are asked to follow the steps of the scientific method and design their own experiment to test this statement. After class discussion about the weaknesses/strengths relative to their designs, the instructor introduces a planned experiment involving the students and tongue twisters. Class data is compiled and the instructor leads the class in a discussion about the results and how they compare to other results.
Time Needed: This activity takes about 30 minutes.
Materials Needed: If interested in compiling class data: a calculator, an Excel spreadsheet, or clickers.
1. Engage your students with a fun survey. Ask them a few questions, “Who is better at ______, men or women?”
Fill in the blanks with these ideas, based on “Sex Differences in the Brain,” Scientific American,, Sept 1992 by Doreen Kimura:
a. Fine motor skills (putting pegs in small holes, needle-pointing, surgery)
b. Learning a new route from a map
c. Remembering landmarks on a new route
d. Matching items that are alike (among a sea of similar items)
e. Spatial ability (rotating pictures of 3D items visually)
f. Naming objects in a category (i.e. name all objects you can think of that are red)
g. Articulation of words
2. Explain that on average, men have been found to excel at b and e, and women excel at the other activities.
(Based on “Sex Differences in the Brain.” Scientific American, Sept 1992 by Doreen Kimura)
3. Ask students, “Is this real? How was it tested? What could account for these differences?”
The article referenced above will give you a brief review about what might account for these differences. “Differing patterns of ability between men and women most probably reflect different hormonal influences on their developing brains. Early in life the action of estrogens and androgens (male hormones chief of which is testosterone) establishes sexual differentiation.” -Doreen Kimura
4. Choose one of these topics to focus on. I have chosen articulation. Explain articulation difficulty by having the students repeat this statement several times.
“We surely shall see the sun shine soon.” The students will recognize that this is a tongue twister.
5. Instruct the students to do this activity: “Using critical thinking, design a scientific approach to see if there is evidence for this statement, ‘Females are better at articulating than males.’ In your answer, you should write out the steps of the scientific method.” (If students have not yet had a mini lecture on these steps, this would be the time to do this.)
6. Allow them time to share their ideas for an experiment with classmates. Allow other classmates to comment on their designs. (To encourage participation here, you might have the groups switch ideas and read each other’s ideas.)
7. After a discussion period, tell them you had an experiment already planned (It is possible that they have come up with something similar. Now is a great time to stress to them that there are often a myriad of experimental designs to answer the same question. Science is creative.)
8. Detail your experimental design to them:
Observation: Females articulate better than males.
Question: Are females better at articulating than males?
Hypothesis: Females perform better on tongue twister challenges than males.
Prediction: If told to repeat a tongue twister 5 times as quickly as possible, then females will successfully complete the task faster than males.
Experimental Design: Students will be asked to work in small groups to time members of their group. They will collect data for each female and male in their group. The tongue twister the students will repeat is “a box of mixed biscuits in a biscuit mixer.” Have each student repeat it 5 times without errors and record this time in seconds. This will likely lead to laughter and fun and a noisy room!
9. After the class completes their group tasks, if you can manage to do so quickly, the class data can be compiled and averaged. (If your class is large and you are using clickers, you might quickly collect the data from the class by setting up MC options for ranges and show a quick histogram or collect open-ended answers and quickly manipulate a spreadsheet. The majority of my class completed it in under 17 seconds, but there were many that reported over 23 seconds.)
10. Be sure to discuss any weakness of the design and sampling errors. Are there other ways to test this skill? Can we now call this a theory? (One example of something to point out is that the males and females would need to be similar in every aspect aside from sex; for example, their average age should be the same. Depict an obvious pitfall if the males were all under 6 years of age and the females were college-aged.)
11. Lastly, let them know that this was a real experiment; it was one task in a series of experiments performed by Doreen Kimura and Elizabeth Hampson of the University of Western Ontarioin Canada. On average, women were faster than men when asked to repeat the sentence 5 times; women averaged 17 seconds. (Interestingly, the scientists found that the women’s values varied depending on where they were in their menstrual cycle. At peak estrogen levels at mid cycle, the average was 14 seconds.) When my class data didn’t match the reported data, I used it as an opportunity to explore the weaknesses of our specific design (no official unbiased data collector, reporting on peers, noisy room, uneven number of males and females etc.) Additionally, I used it as an opportunity to explain how science needs to be repeatable and what it means when a scientist can’t repeat another scientist’s experiment.
To see a discussion of the research on articulation: “Women’s skills linked to estrogen levels.” Science News, Nov 26, 1988 by Rick Weiss.