Questions 1-4:
Indicators (participants field of study, gender, class & how religious they sensed themselves).

Questions 5-8: 
SPI - Selfishness and personal interaction (how selfish the participants act -> selfish is defined as pursuing personal benefits at the expense of a known detrimental effect on another known person).

Questions 9-12: 
MIAE - Market interaction (a person's readiness to give up personal benefits in order to contribute to a more significant societal, moral benefit).

Question 13-18:
ECHC - Egalitarian, cooperative vs hierarchical, competitive choices (individual’s support for competitive and meritocratic systems).

Preliminary sample: 

The noticeable difference in selfish behaviour between male and female students could be a fruitful lead for future inquiries.

We agree with the concern that it would be more optimal to have more participants in our survey to draw conclusions. However, this is also why we mentioned in our essay that our results are just preliminary and a first outlook on the findings of an ongoing study. We were generally curious about the morality of different students and even if we could have drawn a more precise conclusion with a bigger sample, we believe that we got a pretty good general idea of the mindsets of various kinds of students in the first step. The final results will solidify the statistical significance of the findings and will either reject or first findings or emphasise them. The latter being our expectation.
One also has to keep in mind that the USA is a much bigger country with many more students than Austria so even if we were able to come up with a sample size e.g. three times bigger than ours now, in absolute numbers it would still be much smaller compared to some US samples. Besides that, also the majority of US studies worked with a pretty small sample size, still ensuring significant results like the one of the prisoner dilemma with just 30 students.

Critique that "using papers from the '90 is not appropriate" and that "methodology part is too long":

We understand that older literature might not represent today's situation in an appropriate way. However, one must note that there does not exist contemporary literature on that topic, which was relevant for our case. Recognising this lack in literature, we conducted our own survey and focused the main part of the essay on that, describing the highly relevant situation of today.

Critique that there might be a non response bias in the survey and that "selfish people might not consider themselves being part of it":

While of course it can always happen that someone isn't honest in a survey and makes themselves look better than they are, we have faith that since it was an anonymous survey, the participants would answer it honestly. And we don't believe that "only selfless people participated" because the survey was spread among many kinds of people and there were no direct questions like 'do you consider yourself selfish' that might trigger selfish people to not take part in the survey anymore, but rather focused on scenario based questions. However, we recognise the critique and will try to further improve the survey design and questions in following studies to further decrease the possibility of dishonest answers and a non-response bias.