Why are some African countries more emotionally expressive than others?

Gallup recently published results of a global poll on people's propensity to express or report feeling emotions. The Washington Post has a nice color-coded map of the results here.  While some regions exhibit trends-- the Americas are bubbly with emotion, while the former Soviet Union is more somber-- Sub-Saharan Africa has a lot of variation. What country characteristics might be associated with increased emotional expression in Africa?

I decided to test the relationship between emotionality and wealth as measured by PPP-adjusted GDP per capita, predominant language (a proxy for colonial influence by France or England), and whether at least half the population was Muslim.  I used a linear OLS regression; results are below:

There was no significant relationship between wealth and emotionality for the African countries. Countries with a Muslim population of at least 50 percent had a slightly higher average emotionality score, but the difference was not statistically significant. 

People in Francophone Africa were, on average, 3 percentage points less likely to report expressing or feeling emotion, a result that was statistically significant. This may not sound like much, but it's a whole standard deviation below the mean emotionality score. (The model also explains more than a quarter of variation in African countries' emotionality scores!)

So why are the Francophones less effusive? A couple hypotheses:
1. Maybe when translated into French, the survey was less likely to result in positive answers for some reason. 
2. The Francophone variable might actually be capturing regional variation, such as lower emotionality in West Africa.
3. The French colonial cultural influence may have included elements of less emotional expression. 

The first issue is hard to address (language and cultural translation is always an issue when trying to compare social tendencies across cultures.) Putting in regional variables could address the second issue. Another interesting thing to look at would be the impact of political instability.  My data, in .dta format for stata, are here:  /uploads/1/7/1/1/1711915/africa_emotionality.dta