Dead Men’s Tales
Forensic scientists can use a variety of clues to construct the identity of deceased individuals. By
analyzing skeletal remains, scientists can infer all sorts of traits. For example, there is a link
between the length of certain bones and height of an individual. This connection is consistent
enough to allow a person's height to be inferred from just a few bones.
Inferring Height
Your upper leg contains a large, single bone called the femur. This long bone stretches from the
hip (pelvis) socket to the kneecap (patella). The length of this bone can be used to roughly
estimate a person's height. To increase accuracy of this bone-to-height relationship, you will also
need to know both the gender and race of the individual. These factors affect the relationship
between long bone length and the individual's height.
OBJECTIVE:
This activity page will offer an experience in:
 Metric measurement
 Obtaining lengths of body parts
 Inferring height from various long bone lengths
 Developing bone/height relation charts
MATERIALS
 Metric ruler or tape measure
PROCEDURE:
Part 1-Inferring Height from Femur Length
1. Work with a partner. Locate your partner's femur.
2. Use a meter stick or measuring tape to determine the approximate
Femur
length
Height
Height
length of this bone in centimeters.
3. Measure the height of your partner in centimeters.
4. Help your partner measure your height and femur length.
5. Share your data with two other teams so that you have information
about six people altogether.
6. Is there a relationship between the length of a person’s femur and
their height? To find out, make a graph of your data.
7. Can you use your graph to predict how tall someone is by
knowing the length of their femur? Try it!
Femur Length
Analyzing Your Results
1. How accurate were you in predicting height from femur length? Explain.
2. How might the accuracy of this prediction be improved?
Part 2-Inferring Height from Humerus Length
1. Use a meter stick or measuring tape to determine the approximate length of your partner’s
humerus in centimeters.
Humerus
Height
2. Measure your partner’s height.
length
3. Record your data.
4. Share your data with other teams so that you have data for at least
four people.
5. Plot your data on a graph. Show the humerus length on the horizontal
axis and the person’s height on the vertical axis. Draw a line through the points.
6. Is there a relationship between the length of a person’s humerus and the person’s height?
7. Measure your teacher’s humerus, and use that data and your graph to guess how tall your
teacher is. Are you right?
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Dead Men’s Tales
Some Notes for Teachers
Part 1-Inferring Height from Femur Length
1. Scientists have found that a person’s height can be estimated from the length of the femur
by using the following formula
Height in centimeters = 2.6(femur length) + 65
As you would expect, there is considerable variation from person to person, and this
relationship is not an exact one, but it does provide a rough estimate.
2. The graph your students get from their data should look something like the one below. It is
likely that the student’s data will not make a straight line, but the points should suggest
where the straight line could be.
Femur Length and Height
200
Height
180
160
140
120
100
80
0
20
40
Femur Length
3
60
Part 2-Inferring Height from Humerus Length
1. Scientists use the formula
Height in centimeters = 3.06(humerus length) + 64.26
to describe the relationship between humerus length and height for females. For males, the
formula is slightly different.
Height in centimeters = 3.26(humerus length) + 59.41
The differences between these two formulas are so slight that the children’s measuring errors
will cover up any gender differences.
2. Student data should produce a graph looking roughly like the one below. Again, the
measurements are hard to get accurately, and the relationship is not exact, so expect quite a bit
of variation.
Humerus Length and Height
170
160
150
Height
140
130
120
110
100
90
80
0
10
20
30
40
Humerus Length
Part 3-Extensions
1. There is also a relationship between tibia length and height. Can your students find that?
Adapted from: www.pbs.org/saf/1203
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