Part 1: Critique of the Data

The article by The Economist on Generational Replacement has three different types of data visualisations.

The first one is a faceted area plot showing the percentage makeup of a sample taken of the US population for a survey. The colours used are of a moderate saturation, which makes the visualisations less jarring (Wickham, 2011). This visualisation seems to function as the narrative “establishing shot” in this

article, which allows us to understand the rest of the article and the visualisations they contain to a greater extent. (Segel & Heer, 2010). The use of faceted plots makes it hard to compare the current differences in relative distribution between the demographics. However, they do allow us to see the temporal changes in the proportion of each age group over the decades. The visualisation also allows us to interpret the values on a common vertical axis, which is a reliable method of graphical interpretation. (Cleveland & McGill, 1986). Overall, this is an easy visualization to understand and does not require specialist knowledge.

These line charts are displaying differences in opinions on various social issues amongst respondents from different generations. The line chart is a good choice of graph to display temporal changes and allows easy graphical interpretation across a common vertical axis (Cleveland & McGill, 1986). The dimensions of each chart are broadly equal both horizontally and vertically, which prevents distortion of the real rate of change (Tufte, 1984). The dashed black line represents the national average, which contextualises and serves as a useful frame of reference to make interpretations about the responses of each demographic (Tufte, 1984). Short annotations are used, imparting more pertinent information to readers. (Segel & Heer, 2010). A consistent design language is maintained across the 4 graphs, with the only changes being made to the data which it is conveying. This helps the reader stay situated within the narrative the visualisation is trying to impart without confusion that could arise from inconsistent design choices (Segel & Here, 2011). A minor negative would be the lack of a “%” sign on the y-axis, which could result in readers being unsure if the chart is conveying raw numbers or a percentage. The colours used are too similar for Generation X and Millennials and Generation Z, which increases the possibility of misinterpretation by the reader as the colours denote group membership (Ihaka, 2003). However, the clear labelling of the lines mitigate this possibility, and the charts are easy to understand.

This bar chart visualises the differences that can be explained by the generational replacement phenomenon. The bar chart being flipped allows longer and more descriptive labels to be used for each value. This also allows us to compare the lengths of each bar against a common vertical axis (Cleveland & McGill, 1986). A minor critique would be that the white areas of the bar are hard to discern due to the low contrast combination of blue letters on a white background. Moreover, the chart related to marijuana has a higher percentage of change being explained by changing demography than the one directly above it. This is misleading to the viewer as all the other charts are arranged in a descending order.

Part 2: Expanding the Narrative

I shall be using the General Social Survey (GSS) Data from the “socviz” package from Healy (2018). The GSS records the self-identified religion of the respondents, so the data will allow us to visualise the changing religious makeup of American society over the years. Religion has played a large role in American society, politics, and can be key in determining an individual’s value system. This is often be a large predictor to an individual’s stance on particular issues. This makes data about religion of keen interest in both academic and professional settings. For example, the issue of voting has keenly polarised around religious lines in the past, with a higher percentage of evangelical Christians voting for Donald Trump in the 2016 Election as compared to the general voting population. I have chosen to use a line chart due to the ease of graphical interpretation along a common vertical axis and suitability for displaying temporal changes.

The first chart displays trends in Religious identification from the years of 1972-2016. The percentage of respondents who identify as Protestant has fallen over the years, while those who self-identify as having no religion or “Others” has risen. Judaism and Catholicism have remained relatively stable across the decades. This shows that Americans are getting less religious and more religiously diverse. I have utilised a qualitatively different colour scale, as religion is a categorical variable. The y-axis is labelled on the left as opposed to the right as it was in the article as left to right is the most natural reading direction. I have also included the

% unit on the y-axis as it makes it clear that the chart is displaying a percentage rather than raw numbers. The chart dimensions are also approximately the same distance height-wise and length-wise, in order to prevent the distortion of the rate of change (Tufte, 1986)

The next chart is also a line chart that shows the change in the percent of respondents in each generation who self-identity as belonging to a religion. This enables us to delve deeper and investigate if there is a generation gap at the heart of the less religious nature of American society over the years. I have used a diverging palette, with more clearly distinguishable colours than in the article. The % unit is used for the same reason as the first graph. The line chart shows that generational replacement is once again responsible for most but likely not all of the decline in religious affiliation. The three older generations have largely remained at the same level of religious affiliation. We can see that younger generations are less likely to be religious, barring a few outliers in the early years likely caused by small sample sizes. Further investigation would be required to determine if this was the cause for the fluctuations in certain years. The decline within the generations probably explained by older members of a generation dying out or making up a smaller percentage of the total as younger members of the generation turn 18. This once reinforces the point of the article that generational replacement explains a lot of the transforming nature of society rather than an individual changing their mind, in this case applied to the concept of religion.

Taking a wider ethical viewpoint, morality in human civilisation has often been guided and shaped by organised religion (Hare, 2019). Although moral standards in society have undergone complete transformations in the preceding millennia, future where it plays a smaller role is one that can be regarded as uncharted territory