DEMOGRAPHICS
Page 4-1
CEMETERY DEMOGRAPHY
Adapted by Robin Gibson-Brown for Distance education from:
Luczkovich, JJ and Ambrose, WG, “Cemetery Demography”, Laboratory in Environmental Biology, p. 47-56.
OBJECTIVES
This lab will enable the student to:
 understand some of the basic concepts of:
 population demography and life tables
 survivorship, mortality and population age structure
 understand how various factors such as disease and war affected human demography over
the past 150 years.
 evaluate any observed trends in human survivorship and speculate on the reason for any
differences.
MATERIALS




data sheets
pencil
calculator
computer (optional for graphing )
Local cemeteries are an excellent place to complete human demographic studies. They are an
easy place to obtain birth and death dates for hundreds of persons. These data will allow for a
historical analysis of demographic changes over the decades. Specifically, you can create a static
life table (a life that averages death rates over many generations), calculate average death rates,
and graphically represent the survivorship data on human populations living in an area by
examining trends in the data. Also, data collected from different time periods, in different
cemeteries with religious and ethnic differences, and from different geographical areas can be
compared using survivorship curves to look for demographic patterns.
Life tables summarize patterns of mortality experienced by a population as a function of age.
For population ecologists, life tables contain the raw material for understanding population
dynamics and enable them to construct survivorship curves that demonstrate the mortality rates
for a specific population for a specific time period. Life tables have the following components:
1. age interval (x); for instance, 0-5 years, 10-20 weeks, 4-5 days, etc.
2. number of individuals present at the beginning of a specific age interval (nx); in other
words, the number of survivors from the last interval
3. number of individuals dying within a specific age interval (dx)
4. proportion of individuals of the total population present at the beginning of a specific age
interval (lx)
DEMOGRAPHICS
Page 4-2
There are two kinds of life tables that utilize the data collected differently. The first is a cohort
life table which, in theory, is the simplest way to obtain a survivorship curve because it follows
the mortality schedule of a group of individuals within a species that were born, hatched or
germinated at the same time (cohorts). These individuals are exposed to the same
environmental factors, and their survival is followed by documenting the ages at which
individual members of that cohort die. This method is not feasible for species with a lengthy life
span.
Alternatively, the survivorship of long-lived species such as humans can be studied when the age
of the remains of dead organisms can be determined. A static life table averages death rates
over many generations. Local cemeteries are an excellent place to complete human
demographic studies, or the statistical study of populations because it is easy to obtain birth and
death dates for hundreds of people in the region. These data facilitate a historical analysis of
demographic changes over the decades and can be used to calculate the average death rates for
an era and determine survivorship trends on human populations living in an area. Data collected
from different time periods, in different cemeteries representing religious and ethnic differences,
and from different geographic areas can be compared using survivorship curves to look for the
demographic patterns for different eras, religions and ethnicity.
Three time periods were selected for studying how populations change based on the year of
death: pre-1900, 1901-1945, and 1946-present. These periods correspond roughly to the preindustrial period during the Civil War, the post-industrial period from World War I to World
War II, and the post-World War II period until the present. Changes in health care and largescale regional and global wars have had marked effects on the demographics of our population.
For the time periods we are considering, think of the factors that may influence your data. In
particular, think about disease epidemics, pre-natal care and changes in infant mortality and
childbirth-related deaths, major wars, etc.
In order to study the entire human population that once lived in New Bern, we would have to
visit all of the local cemeteries and assume that no one emigrated (left the area) and were buried
elsewhere or immigrated and were buried locally. We will assume that the cemetery we will
visit is representative of all people living in this area, although we should be aware of any
potential biases in the data.
There are three types of survivorship curves: early mortality, constant mortality and late
mortality. Early mortality describes the condition where most individuals are lost at infancy or
early in life. For constant mortality, there is a steady decrease in the population throughout the
lifespan of the individuals. Late mortality identifies the trend where most individuals survive
until the end of their lifespan. Do any of these trends describe the periods we are studying? We
will determine this when the data is graphed and speculate on possible reasons for any
differences. Also, we will evaluate any differences between males and females.
DEMOGRAPHICS
Page 4-3
PROCEDURE
1. Go to a local cemetery with numerous tombstones that has old graves that date back to the
1800’s as well as now. You will collect data from three different assigned time period, pre1900 (Table 4-1), 1901-1945 (Table 4-2) or 1946 to present (Table 4-3).
2. On the appropriate table (4-1, 4-2, 4-3), record the individual’s initials (to avoid
duplications), the year of death, and calculate the age at death while you are in the cemetery.
Take a partner (or several partners)with you so it takes less time to collect the data.

Separate the statistics for men and women.

If you are unsure of the individual’s sex, make your best guess.

Infants below the age of 1 should be listed as age 0.

Obtain a minimum of 50 males and 50 females for each period.
3. Generate a static life table (number surviving per 1000 individuals), separating males and
females, for each time period in Tables 4-4, 4-5 and 4-6 by following these instructions:

In COLUMN 1, “x” denotes the age interval where x = 0 for 0-9 year olds, x = 10 for 1019 year olds, etc. The subscript “x” in subsequent columns identifies the interval for
which you are performing calculations (nx can refer to n10, n20, n30, etc.).

COLUMN 2 represents the age interval of individuals in years.

The number of individuals present at the beginning of the age interval (nx) is calculated in
COLUMNS 3/7 by subtracting the number of deaths in the previous row from the number
present at the beginning of that interval.
nx = nx-10 - dx-10
for x = 0, use the number of graves in sample

In COLUMNS 4/8 record the number of deaths per age interval.

Calculate the proportion surviving from birth (lx) in COLUMNS 5/9 by dividing the
number of individuals present at the beginning by the total sample size (the value of n0).
lx = nx / nx-10

for x = 0, divide n0 by n0 - the value is always 1
In COLUMNS 6/10, calculate the survivorship of the population:
(lx) x 1000
4. In Figure 4-1, generate a graph (using paper and pen or a computer) of your data with
COLUMN 1 (x) on the x-axis and the Survivorship per 1000 (COLUMN 6/10) on the y-axis.
Record all time periods of data that you collected on the same graph using separate curves for
males and females. There should be SIX different lines represented on this plot; therefore,
include a legend. I would suggest using the same colored pen for the same time period and
differentiating between males and females with a different symbol; this will help in your
analysis. This graph should be in your notebook along with all your data sheets.
DEMOGRAPHICS
Page 4-4
Table 4-1
RECORD OF DEATHS: Pre 1900’s
MALES
Initials
Year
of
Death
Age at
Death
Initials
FEMALES
Year
of
Death
Age at
Death
Initials
Year
of
Death
Age at
Death
Initials
Year
of
Death
Age at
Death
DEMOGRAPHICS
Page 4-5
Table 4-2
RECORD OF DEATHS: 1901-1945
MALES
Initials
Year
of
Death
Age at
Death
Initials
FEMALES
Year
of
Death
Age at
Death
Initials
Year
of
Death
Age at
Death
Initials
Year
of
Death
Age at
Death
DEMOGRAPHICS
Page 4-6
Table 4-3
RECORD OF DEATHS: 1946- Present
MALES
Initials
Year
of
Death
Age at
Death
Initials
FEMALES
Year
of
Death
Age at
Death
Initials
Year
of
Death
Age at
Death
Initials
Year
of
Death
Age at
Death
DEMOGRAPHICS
Page 4-7
Table 4-4
STATIC LIFE TABLE: pre 1900
1
2
3
4
5
6
7
MALES
(x)
Age
Interval
, years
0
0-9
10
10-19
20
20-29
30
30-39
40
40-49
50
50-59
60
60-69
70
70-79
80
80-89
90
90-99
100
100109
# Present at
Beginning
of Age
Interval
(nx)
# of
Deaths
per
Age
Class
(dx)
Proportio
n
Surviving
from Birth
(lx)
nx / n0
8
9
10
FEMALES
Survivorship
per 1000
# Present
at
Beginning
of Age
Interval
(nx)
# of
Deaths
per Age
Class
(dx)
Proportio
n
Surviving
from Birth
(lx)
nx / n 0
Survivorship
per 1000
DEMOGRAPHICS
Page 4-8
Table 4-5
STATIC LIFE TABLE: 1901-1946
1
2
3
4
5
6
7
MALES
(x)
Age
Interval,
years
0
0-9
10
10-19
20
20-29
30
30-39
40
40-49
50
50-59
60
60-69
70
70-79
80
80-89
90
90-99
100
100109
# Present at
Beginning
of Age
Interval
(nx)
# of
Deaths
per
Age
Class
(dx)
Proportion
Surviving
from Birth
(lx)
nx / n0
8
9
10
FEMALES
Survivorship
per 1000
# Present
at
Beginning
of Age
Interval
(nx)
# of
Deaths
per Age
Class
(dx)
Proportion
Surviving
from Birth
(lx)
nx / n 0
Survivorship
per 1000
DEMOGRAPHICS
Page 4-9
Table 4-6
STATIC LIFE TABLE: 1946-Present
1
2
3
4
5
6
7
MALES
(x)
Age
Interval,
years
0
0-9
10
10-19
20
20-29
30
30-39
40
40-49
50
50-59
60
60-69
70
70-79
80
80-89
90
90-99
100
100109
# Present at
Beginning
of Age
Interval (nx)
# of
Deaths
per
Age
Class
(dx)
Proportion
Surviving
from Birth
(lx)
nx / n0
8
9
10
FEMALES
Survivorship
per 1000
# Present
at
Beginning
of Age
Interval
(nx)
# of
Deaths
per Age
Class
(dx)
Proportion
Surviving
from Birth
(lx)
nx / n0
Survivorship
per 1000
DEMOGRAPHICS
Page 4-10
Figure 4-1
SURVIVORSHIP CURVES FOR THREE TIME PERIODS IN ______________________
1000
900
800
Survivorship per 1000
700
600
500
400
300
200
100
0
0
10
20
30
40
50
60
Age Interval (x)
70
80
90
100
110
DEMOGRAPHICS
Page 4-11
QUESTIONS to be answered in complete sentences
1. Describe the graph you generated in Figure 6-1. What type of survivorship curve have you
generated for EACH time period? Your choices are: early mortality, constant mortality
and late mortality. Do not evaluate males and females separately, generalize your answer
based on time period alone – not all choices may be used.
2. What might cause the changes in survivorship trends between the time periods?
3. Which time period has the shortest life span? The longest?
4. Throughout history, are there any differences between the life spans of men and women?
Support your answer by citing statistics from the data you collected. Speculate on the reason.
5. Speculate on the survivorship trends for the population if the following scenarios are realized.
Describe any changes in the curve, mortality rate and life span of the population.
a. AIDS cases in our society continue to increase and there is no hope of a cure.
b. Medical advances continue, eliminating all life-threatening diseases.
6. Based on your knowledge, sketch a survivorship curve for a third-world country that has a
high infant mortality rate. Add another line that demonstrates survivorship if infant mortality
were greatly reduced and there is now a constant mortality rate. Provide a legend for these lines.