This is part two of the Survivor Survival Analysis series. The first one gives an introduction on Survivor Analysis and looks at KM survival curves for age, sex, and geographic stratifications.
In this post, we look at survival curves stratified by the ‘era’ of Survivor, i.e. the unofficial monicker of Old School and New School, in addition to the demographic stratifications in the first article.
The distinction of Old and New isn’t really set in stone. There’s actually a Reddit thread where people debate on where Old ends and New starts. The comment which I agree with the most is the one by PopsicleIncorporated, with Tocantins being the end of Old and Samoa being the start of New. That’s the division I’m going to use in all that follows.
The goal of this post is to see if there are significant differences in the survival curves for Old School and New School. And if I can, I’ll try to account for these differences.
Sound off in the comments below if you have some thoughts on what changed in the game of Survivor which led to survival curves changing over time.
Survival by Sex
In Old School Survivor, there is a reversal between female and male on which sex has the higher survivability. Early on, males have the upper hand, but it shifts around Day 27 when females attain higher survivability. In the New School era, this reversal does not happen, and all throughout the game, males have higher survivability than females.
I wonder why this is the case.
Survival by Age
This is really interesting. In Old School Survivor, old people tend to have low survivability up until around Day 30, while in New School Survivor, they tend to have high survivability overall. In addition, in New School Survivor, old castaways have a higher survival probability than young ones, while this reverses in the Old School era.
One idea I have on this is that Old School Survivor tends to focus more on who is more deserving, and one of the main qualities that people tend to focus on was physical prowess and contribution to camp. By the nature of ageing, old castaways tend to have lower physicality and thus get voted out as a physical liability. On the other hand, New School Survivor is much more strategic, and the focus shifts to eliminating threats – starting off with the physical threats when given the opportunity. Thus, old people are able to go under the radar since they oftentimes are overshadowed by these threats.
Survivor Survival Analysis
There are a lot of things that can still be done with Survival Analysis on Survivor data. All we have been doing is estimating the survival function with the Kaplan-Meier method. We haven’t really touched on statistical inference on survival rates.
What we can do in the future is apply the Cox Proportional Hazards Model to see how the different demographic covariates affect the hazard function, which can be interpreted as the instantaneous ‘risk’ of dying, opposite of what the survival function represents. Using the Cox PH model, we can quantify how age, sex, geography, and basically any variable affect the hazard of getting voted out (and in turn, the survivability). But let’s save that topic for a rainy day.