Human Demography: Comparison Of Survivorship And Life Span Of Males And Females
Abstract
Demography and survivorship describe population characteristics, such as age-specific survival and life expectancy of a specific species. Survivorship graphically represents the life expectancy through three types of curves: type I, type II, and type III. These curves represented the male and female data found on the cemetery tombstones. Tombstones were broken into three categories, depending on death year, in order to avoid overlapping data. Male and female survivorship data showed different results due to multifaceted reasons and different sociocultural perspectives during different given years.
Introduction
Population size changes through the effects of birth, immigration, deaths, and emigration. Survivorship and demography help understand human longevity through the lens of the effects of population size changes. However, the purpose of this study was to study the birth, survival, and death of the given population. Survivorship curves were created for three sections of the population- females and males who dies pre-1901, females and males who died between 1901-1950, and females and males who died post-1950. Other studies provide insight as to why survivorship curves between females and males were different depending on given years, such as the fact that women throughout the 1900’s were more domestic and rarely held a job outside of societal demand, whereas men were doing more labor-intensive work and going off to war. Data was collected from a town cemetery in Farmville, Virginia and pre-organized into categories in order to calculate age of death of the females and males buried there. The hypothesis that was tested during this study was that the females and males in the pre-1901 group and the 1901-1950 group had less of a chance of surviving compared to the post-1950 group because of warfare, lack of proper medical care, cultural norms, and genetic predispositions. Furthermore, we are hypothesizing that males have less chance of surviving across the board than females.
Methods
Data was collected from Westview Cemetery in Farmville, Virginia. In order to avoid overlapping data points, the headstones were split into different sections. Data was recorded by different groups by the age of death. Groups 1 and 2 recorded females and males who died before 1901, groups 3 and 4 recorded females and males who dies between 1901 and 1950, and lastly, groups 5 and 6 recorded females and males who dies post-1950. If the names on the headstones were not legible or the name does not determine the gender of deceased, that headstone was omitted from the record. In total, at least 100 data points were collected encompassing all sections. All data points were then entered into an excel spread sheet and analyzed.
Data Analysis
The collected data within the excel sheet was analyzed with a two-sample t-test that found the average, standard deviation, and standard error for females and males from pre-1901, 1901-150, and post-1950. These numbers were then used to create survivorship curves and bar graphs showing the average life span of the females and males in Farmville, Va.
Results
Our study found that females had a longer life span than males during pre-1901, 1901-1950, and after-1950. The oldest age of death for a female for pre-1901 was 41 years old, while the male was 37 years old. The same results occurred for the 1901-150 group with the oldest female being 56 years old and the oldest male being 54 years old. Post-1950 contained the largest difference between ages of death with the oldest female being 74 years old and the oldest male being only 67 years old. These result support our hypothesis that females would survive longer than men across the board in all three groups. Our second hypothesis was also proven true in that females and males in the pre-1901 and 1901-1950 groups had less chance of surviving compared to the post-1950 group. The bar graph shows the first two bars are smaller than the last bar that is representing post-1950 (Figure 2). Statistics show that the exact average life span, using t-values, for females was -9. 4935 with a p-value of 1. 763e-12. The exact average life span, using t-values, for males was -7. 257 with a p-value of 1. 496e-10. Females and males pre-1901 show a type III survivorship curve, meaning the people alive during that time faced high mortality rates and did not age very far. Females and males from 1901-1950 show a type II survivorship curve, meaning they face a more constant survival rate. Lastly, females and males post-1950 show a type I survivorship curve, meaning they face high survival rates, low infant mortality, and survive till old age. However, in all survivorship curves, females show a higher survivorship than men.
Discussion
The results from the bar graphs and survivorship curves show a significant difference in the average age of death. Females tend to out-live men for multiple reasons. As stated before, in the early 1900’s, women were more prone to taking care of the household instead of hands-on labor in the work force that carries more risk. Genetics also play a role in as to why females survive longer than men. Females have different biological makeups than men, which allows for the different results we found during our study. Some of the biological differences include, hormonal and cellular responses to stress, immune function, and metabolic substrate handling among others. Race also plays a part in the difference of age of death for females and males - specifically in Farmville, Virginia. Farmville is a predominantly African American male community- meaning they have predisposed genetic deficiencies, along with more of a chance of catching topical or internal diseases.
Survivorship curves are able to show how human population dynamics change over time in Farmville. Based off of our results, we can conclude that the pre-1901 survivorship curve was type III because of the lack of resources available, such as food, proper medicine, and vaccinations, meaning the population would rapidly decrease. Groups 1901-1950 and post-1950 are type II survivorship and type I survivorship, which makes sense considering as the years progress, modern medicine has been implemented and there are more resources available for the population demand.
Some limitations of the study include inconsistencies when collecting data; there were more male tombstones than female tombstones in the cemetery. We only collected data from one cemetery in Farmville instead of multiple cemeteries. The last limitation with this study was the amount of data we collected overall. A set of 30 data points is an alright amount of data to collect, however, with our study, some of the data we collected did not reach 30 data points. After this study, we were able to generate more questions, such as, what would be the results if we expanded our field study area? Does upbringing have an effect on the age of death of females or males within a population? In the future, these are the questions we could ask to go into depth on human demography and survivorship of males and females in Farmville, Virginia.
References
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