Naked and Afraid Statistics

Quote of the Day

The Soviets are our adversary. Our enemy is the Navy.

Curtis LeMay, General, US Air Force. Anyone who has worked on a US military defense contract knows about interservice rivalry. General LeMay was the prototype for General Turgidson in the movie Dr. Strangelove.


Updated 16-Aug-2017. I added all the episodes to date. I have also began filling in the table with new data like weight loss, military experience, and the type of build the men have. It will take time but I will eventually get all this data filled in.

Introduction

Figure 1: Locations of 2-Person Naked and Afraid Episodes.

Figure 1: Continent Locations of 2-Person
Naked and Afraid Episodes.

I do not watch much reality television, but one show I do watch is Naked and Afraid (N&A). I have always been interested in primitive survival skills (e.g. I have blogged about knot tying and rigging), and this show really puts those skills to the test. I like the fact that the participants are presented with survival challenges from around the world (Figure 1). They have been on all the continents but Antarctica – I could not imagine someone surviving naked in Antarctica for any length of time.

While watching N&A recently, my wife sat down with me and made some observations that I thought I could test. Here were her questions:

  • Are the women younger than the men?

    I had not thought about it until my wife mentioned it, but the women do seem younger than the men.

  • Do the women have lower Primitive Survival Rating (PSR) scores than the men?

    It does seem like the women have lower PSR scores than the men. That may be a function of the women being younger than the men, or the fact that the rubric is heavily weighted toward the kinds of employment that men tend to have.

  • Is the start-to-finish PSR change for men the same as for women?

    My personal feeling is that the women start out lower and end up lower, but this should be easy to test.

I gathered all the data on the participants that I could, which was more difficult than you might think.

Background

Definitions

Primitive Survival Rating (PSR)
A metric for evaluating an individual's level of primitive survival skills on a scale from 1 to 10. The show's producers say about the metric is that it is established by a team of experts who evaluate the participants at the beginning and end of each episode, but they do not provide a rubric for its evaluation. People who regularly watch the show can see that the metric is heavily weighted toward people who regularly practice their survival skills – such as survival educators.

Approach

I gathered all the data into a spreadsheet (here) and imported the data into R. I then used ggplot2 to plot the data. I tend to use box plots, which I find quickly give me a good feel for the distribution of the data.

Analysis

I should comment on notation. Box plots show the median as a dark bar in the "center" of the plot. I also like to include an annotation for the distribution mean, for which I use the symbol μ.

Are the Women Younger Than The Men?

On average, yes (Figure 2) by about 3 years.

Figure 2: Male and Female Age Distributions.

Figure 2: Male and Female Age Distributions.

Do the Men Have Higher PSRs Than the Women?

On average, yes (Figure 3) by about 0.65. This difference seems to maintain from start to finish.

Figure 3: Comparison of Starting and Ending PSRs.

Figure 3: Comparison of Starting and Ending PSRs.

Note that the mean and median for the women are quite different from each other.

Is the Start-To-End PSR Change Same For Men and Women?

The average change is very similar, with women having a wider distribution (Figure 4).

Figure 4: Change in PSR (Start-to-Finish) For Men and Women.

Figure 4: Change in PSR (Start-to-Finish) For Men and Women.

Conclusion

I believe that I have answered my wife's three questions. I do have some questions of my own that I want to address. One question that I have is whether the PSR difference between men and women has any correlation with the fact that the women are younger. This will be a subject for a later post.

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47 Responses to Naked and Afraid Statistics

  1. Paul Campbell says:

    Mark,

    Can you make your data available, so I can have my stats students work on it?

    Thanks,

    Paul C

     
  2. Maureen Walther says:

    How many men and women have made it to the end?

     
  3. Don't the PSR scores appear to be SO sexist!?! I watch the show a lot and it drives me insane! There aren't huge differences between the men and the women in most cases, and the women never get as many points added as the men when they make it to the end. It makes me crazy!

     
    • mathscinotes says:

      I wrote the blog post after my wife made the same comment. I wanted to try to understand why women's PSRs always seemed lower. I haven't wrote a post yet on the topic, but age appears to be a significant factor in determining the PSR, and the women on the show are usually younger than the men. Why are the women usually younger? I would speculate that it is television, and they want younger women for the ratings.

      mark

       
      • LB Wilson says:

        It’s funny that you say “age” is the factor when I think what you mean to say is “sexism”

         
      • Monique Cummings says:

        I don't think the women are younger for ratings. It's only 3 years. My guess would be that women with children would be more hesitant to go, so women without children (younger) are more willing to go.

         
  4. Carolyn says:

    Thanks for your blog. I was also wondering about the PSR/gender gap as well. I would hypothesize that the women's lower PSR is not due to their age, but due to the lower propensity for staying emotionally and physically healthy, perhaps from being colder at night and getting less sleep? However, I have seen many very strong women and conversely several men that have been overwhelmed emotionally or tapped out. Keep up the good work!

     
    • mathscinotes says:

      I want to perform a more detailed analysis of the data, but I am in the middle of building a new house. I plan on updating the spreadsheet with data from some recent episodes and then do a set of hypothesis tests.

      Thanks for the comment.

      mark

       
    • m. genesi says:

      I have been watching this program from the beginning, I cannot believe some of the man, all the seem to bring a massive ego and very little else, argumentative, no skills, and no mental toughness . big ex military man good on killing people but useles in survival skill without a firearm. And then there was an effeminate mommy's boy who had zero skills, in contrast the woman thought by her father was superior in absolutley everything. He cut himself after taking over from the woman who was doing alright thank you very much! He tapt out after only 3 days whining in non existing agony, as he was told by the medical team tht there was nothing wrong with him, he made me feel ashamed of belonging of the same sex, while the woman completed the challenge .Woman mental toughness has seen them finish the challenge while man seems to give up

       
  5. Jennifer says:

    What i really want to know is how many men complete it alone compared to women. It may be my imagination but it seems that women finish alone more often......

     
  6. Nicole says:

    I appreciate this data. I'm trying to dig deeper in the stats of this show.

    I just ran across this show today and was so disappointed in the flagrant sexism. I honestly want all women to watch this show to see how it is a perfect example of how women are undervalued from the start and also undervalued when they succeed in comparison to their male counterparts.

     
    • mathscinotes says:

      My wife and I have had this same discussion. That is part of what motivated my data gathering. I will be working more on the stats myself.

      mark

       
    • m. genesi says:

      I agree, but actually makes the man look even worse, when they tap out, which they do, more often than woman. I am beginning to ask myself, where do they get this men from! It has got to the point that that at the beginning of the program, I play a game with myself,... Is the man going to tap out? last night after only a few minutes I knew that the man was going to give up, which he did after 14 days . some of them start by chopping everything on site, in spite of the woman advising to save energy, some give up because of injuries sustained by taking stupid risks, or drinking contaminated water. one particular man started to sustain sunburns after only two days, and was useless for days,and ( I am not making this up!) he chose as a choice tool under water goggles to fish, only he did not like going underwater!!, Another refused to eat food provided by the woman, as he failed in his attempt to find any, his male ego would not let him, and yes he give up! Of course I knew that the female body is more suited for survival when the resources are scarse, they have to be, they are the keeper of the human race. So yes I will expect more man than woman tapping out in future episodes.

       
    • Pamela says:

      Why can't you just watch the show for what it is, entertainment. Not everything has to be about feminism, race, etc.

       
      • Imhere says:

        The misandry in this comment section is unreal. I swear women have developed some sort of massive inferiority complex. They are CONSTANTLY trying to prove they can compete with men. Who cares?? It's like nearly ever woman you meet online has some sort of Napoleon complex. I think it's directly related to feminism.

         
  7. Christal Cookenmaster says:

    Great info! My husband has been called back for this show so we're looking for ALL the info we can get!

     
    • mathscinotes says:

      I will be updating this post and adding an additional post with more statistics. It is amazing how much traffic I am getting on this topic lately. Good luck to your husband – N&A is the toughest outdoor challenge I know of.

      mark

       
  8. Ed says:

    I think the women on N&A are getting short-changed in their final PSR.

    It seems like some of the women that have completed the 21 day challenge should be rated above 8.0 and I'd say that some women should be rated higher than their male counterparts.

    Having watched N&A from the beginning, I'd say that some of the women have been much stronger than the men.

    I wonder, How would two women fare on a 21-day N&A challenge?

     
    • mathscinotes says:

      The two women versus two men scenarios would be interesting to see. I have several other theories that I would like to test, but I don't have the data I need:

      • large men versus small men.

        It seems that smaller, more wiry men do better than the big, hulking men. I would like to test that out, but I have no size data.

      • married versus single.

        Do married people tend to have better teamwork skills than a single people? I don't know.

      • military experience versus no military experience.

        The Green Beret in the "Surthrive" episode hit the ball out of the park, but I am not sure that is true in general – he was singularly impressive. We have now seen quite a few female veterans, so I think we could do a statistical test on the value of military experience for both male and female participants.

        I am busy building a cabin in Northern MN right now, so I have no time to spend on these theories. I will say that N&A provides many opportunities for practicing my statistics.

        mark

         
  9. Leslie Foltz says:

    I'm curious to know which gender has tapped out the most. It seems to me that as for tapping out, men tend to do so more often than women, since I know for a fact that one woman holds the record for being alone the longest after her partner tapped out on like the 2nd or 3rd day. Any idea what the ratio is?

     
    • mathscinotes says:

      I posted an updated workbook and some information on the solo finishers here. One issue with making comparisons is that if a person taps out early, the show tries to bring in an replacement – usually a person who tapped out on a previous episode (e.g. Amber Hargrove tapped out twice, and is now on for the third time with XL). On some of the shows, I had a difficult time determining the exact day number the person tapped out. I got as close as I could.

      mark

       
  10. Amy says:

    Thank you very much for your wife's questions and for taking the time to compile and make public this information.
    I believe that it would also serve to forward this on to the shows producers. I believe there is some bias in the calculation of the PSR that is evident when you crunch the numbers.
    Thank you again for taking this time and effort.

     
    • Imhere says:

      I think there is a huge bias in family courts, "child support" laws. Child custody laws. I also know there is a huge bias in the way women are convicted for the same crimes as men. They are alot less likely to be convicted, and wen thet are they get ALOT less time. It's quite strange with all these biases, against men in favor of women in REAL life. That these comment sections women are all hurt about the potential that a made up "psr" might be sexist. . But when a bias benifits them in real life. That's not a problem. It's like feminism has created a whole generation of narcciststic women that suffer from severe inferiority complexes, that are constantly trying to prove that men are weak and evil and woman are strong and perfect.

       
  11. Hannah says:

    It is has been interesting watching N&A in light of research I have been doing on the Donner Party. In DP, and other similar survival situations, women, especially younger women tend to fair better than their male counterparts, not for any experience or survival tactics, but simply because their bodies are biologically better built for it. Being smaller, they have lower energy requirements and have a lower tendency to overexert. They also have a higher percentage of fat stores which may also allow them to survive longer without food.
    If these facts were taken into account, I imagine the PSR for women, smaller people and younger people (and even people with a higher percent of body fat), would be higher than larger, muscular men. However, I don't think that's what the show is interested in, nor is it how they determine PSR.
    In this respect, I don't this PSR correlates to actually chance of survival, which may explain why seemingly more men tap out than women, despite reverse PSR ratings.

     
    • mathscinotes says:

      I completely agree. I have not done the analysis yet, but I see older people having a distinct disadvantage for a given skill level. I also believe that large, bulky men have a disadvantage over smaller, more wiry people (men or women). These male versus female debates always get strange at some point. For example, I remember watching a television report about a US Air Force study that said that small women with high blood pressure were the best suited physically to be fighter pilots – their arguments centered on these women being able to sustain high g-forces. The report included interviews with some male pilots who took great offense at the idea that size or gender could affect ones ability to be a fighter pilot. It just makes sense. Similar arguments occurred in the early space program about women astronauts. Their smaller size and lower resource requirements were clear advantages for space travel. But the first astronauts were drawn from the pool of test and fighter pilots, which were all male.

      Not everyone is given the same physical assets for a given task, including survival under tough conditions.

      mark

       
  12. Jessica Sacks says:

    I think you are getting all this traffic because of the Maria the Buddhist episode. I found your post because I wanted to see how many other women have ever had a higher PSR than their male partners. Maria rocked that episode. The only story they could spin was that she was way more capable than her partner. Love it.

     
    • mathscinotes says:

      Thanks for the comment. I will put out a post on the women who ended with higher PSRs than their partner.

      mark

      P.S.
      Laura Zerra has the highest PSR to date for a woman at 9.1. I thought she was amazing.

       
  13. Pingback: NAKED AND AFRAID Who has the all-time highest PSR? The lowest? Survival data galore - starcasm.net

  14. Meghan M says:

    Have you considered performing a t-test on your data? The interquartile ranges in the box plots overlap so I am suspicious about the conclusion that they are actually different.

     
    • mathscinotes says:

      Hi Meghan,

      I plan on putting out a couple of posts using quantitative methods when I finish building my cabin, which should be done in September. I realize that the graphical methods are limited. I am continuing to gather N&A episode data, and I will update all of my old posts.

      Thank you for your question.

      mark

       
  15. Kitt says:

    Great data Mark...delighted to see someone else was interested in the male vs female tap outs. I wondered myself because it seemed so many men whined their way to leaving.

    If possible, can you also do the male/female tap out data that removes those who left because of emergency medical reasons vs just couldn't deal with bugs/environment etc.?

    Thanks for all your work on this site and good luck with that cabin!

     
    • mathscinotes says:

      It is amazing all the Naked and Afraid factors, quantitative and qualitative, that could be tracked. I will add your suggestion to my list. I am looking at adding some factors to my list: military experience, body type (for males), tap out reason, and married/single.

      mark

       
  16. Harlan says:

    My significant 'otter' and I watch all iterations of N&A and we have both wondered what the visual statistics would look like, though the thought of putting the data together myself quite literally gives me hives. (I'm dyscalculic.) Though your site is certainly a more intelligent level of discourse than most, I am still mildly troubled by some of the comments here that are representative of the precise reason I shun social media in all of its forms.

    Are men and women's scores different? Most certainly. The data here is numeric, objective and irrefutable. You have compiled it in such a way that even the non-mathematic can easily see this. However, they SHOULD be scored differently. The simple truth is men and women are different. We always have been and always will be. On a sub-cellular level, we are different. There is nothing at all wrong with this and it is has always baffled me why people are so quick to rail against that as though the mere action of denying would make it so. That having been said, to attempt compare our capabilities using the same rubric is like comparing apples to lug nuts. This is why you are seeing such a disparity in women's scores versus men's scores. It's not that they're being sexist or unfairly scoring women, it's that the stick by which they are measured seems to be tailored to include only easily definable and measurable parameters which happen to be areas where men tend to present greater advantage.

    The survival community is a male-dominated one. This is evidenced by the significant percentage of the archetypal Alpha-male persona that is drawn to this sort of life-style. I'm a native Texan girl who grew up completely exposed to hunting, fishing, fixing cars, catching creepy crawlies just for fun, there's always more boys than girls. That, too, is objective fact.

    I am theorizing here, as no one outside of Discovery's N&A production crew is likely privy to the exact numerical breakdown of what comprises PSR, but those whom I have discussed this with feel I am not far from the mark. A PSR seems to be a relational value between a person's demonstrative knowledge, their proven and tested skill set as it relates to wilderness survival and their outward portrayal of mental attitude surrounding their abilities. How often do you see a contestant blustering on about how they're an extreme athlete and able to scale sheer mountain cliffs with only their nosehairs, and two days into the challenge they're crying about being hungry/thirsty/tired on a pile of dirty leaves? PSR doesn't accurately measure a person's ability to survive. Think of it more of a sliding percentage of how likely they are to be able to successfully complete the physical component of an array of challenges presented to them in a vacuum or at the very least in a baseline-level environment in which needs are met, homeostatic and they are working to further their condition from survival to comfort.

    In short, a PSR is largely irrelevant. Don't get hung up on the numbers. What the PSR lacks is weight in all three categorical spheres of human traits: Physical, Mental AND Emotional. This is not entirely Discovery’s fault, as collective human consciousness is still largely willfully ignorant of these divisions. (IE. If they knew better, they could do better, but they don’t care to so they can’t.) It is a systemic, societal inequality. Granted, an emotional subcategory for a PSR would still be quite imperfect because it would likely rely on the survivalists’ subjective estimations of their own emotional abilities and responses. I cannot impress enough how desperately hard this is to do under optimal conditions. I know. As a practicing mental health professional, I deal with it every day with people from all walks of life, both sexes, all socioeconomic groups. Without bringing in an appropriate panel of psychiatric professionals that truly understand the field of survival and what this challenge is meant to embody, they could not hope to accurately assess the survivalists’ emotional fitness to meet and/or exceed a challenge.

    The problem is this, yes, the PSR scores are sexist. But the larger issue here is, they should be. They should be an accurate portrayal of what a man or woman is capable of. Unfortunately, this will favor men in terms of hard numbers unless Discovery is willing to revise their own statistical analysis to include a category that is connotative and contextual anathema, which, also happens to be the fire from which a lot of these successful women are forged as is evidenced by their impressive performance despite their PSRs being abysmal by comparison. We do not need to picket Discovery to be less sexist, rather, we need to encouraged them to dig a little deeper. Don’t do the easy work and call it a PSR. If they want to measure a human’s capability to survive and be taken seriously in the effort, then include all of the advantages, not just the ones that are simple to read and record.

    To that end, it would be interesting to see what the score breakdown looks like with the following analytical parameters:
    - Of those who tapped, how many were voluntary and how many were imposed by production? Break those down still further into male and female.
    - Of those who tapped, how many were from medical necessity (illness and physical environment not able to minimally sustain life) and how many were mental/emotional conditions? Break those down still further into male and female.

    As a side note, to amend your current data table:
    6:52 Amber Hargrove began with a 7.8 and fell to a 7.4 despite the fact that she was a medical tap out.
    7:60 Michelle’s last name is Etchings.
    7:62 Chance’s last name is Davis.

     
    • mathscinotes says:

      Thank you for the database updates. I will update all posts with this information over the next few days – I am busy building a cabin in northern Minnesota. Also, thank you for the comments.

      mark

       
  17. Margaret Ramsteck says:

    Russell Sage started at 7.1 with Manu in 2013.

     
  18. Nick says:

    I'm not sure how compile the data other than going through each epsisode. Statistics on who built shelters, fires, and provided food would be interesting. I feel like over exertion has a lot to do with people tapping and it may bring some light to why people are tapping. Also there are a couple of episodes where people have tapped earlier and stayed a few days longer with a new parter. I appreciate the work. It's not easy to find data on the show.

     
    • mathscinotes says:

      The initial compilation of data was not difficult because I just watched show and wrote down the names, ages, start and finish PSRs. When I missed a few shows, I just watched the first and last few minutes of the shows on Youtube. I do want to gather information on body type because that appears to play a role. That would entail watching the first couple of minutes of each show and would not be too bad. For a guy who is interested in statistics, the show is a treasure trove.

      mark

       
  19. Jim says:

    Have you collected data on the average weight loss?

     
  20. Katie Jane says:

    It might be more interesting if along with all skills/physical traits used to make up their psr's that they include something known as the grit factor. It can make or break your success and not everyone has it. Maybe use it as a bonus to raise their score at the end? Also, I think there should be a deduction for the person contributing nothing or very little to their survival. That is where the women really get screwed if you ask me. Just having watched the first episode in season 8 I was shocked they gave that guy anything over his initial rating and felt he should've had a big deduction. She was a tad overly concerned about how she was perceived by him as to her abilities - why I don't know - yet truly showed him up in performance all through the show. Even my husband thinks the women are often rated lower and should have the ability to score higher than the man when they outshine them. It's just so unsatisfying and irritates us both.

     
  21. Ernie says:

    Another aspect to add I think would be valuable is people who have faith or religion. All four that come to mind all completed the challenge. And I mean practicing such as praying or practicing their faith while on the show. You have the morman or the Christian a Buddhist and a wicked all completing the challenge

     
    • mathscinotes says:

      Now that you mention it, there are a number of factors that could be important. Have children? Married? Hard upbringing? Parents who were outdoors people?

      I wonder how would I objectively measure their level of faith?

      mark

       

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