In a survey I would like to find out the correlation between different factors based on the personal dimension "being more emotional vs. rational". Are there any known studies with items that could be used to differentiate between those two personalities or validated items in general about this topic?
I know that Helen Fisher, who is a love researcher, has developed a four factor personality model where two of the factors are quite relevant to your question. See (Fisher et al, 2015) for some general information regarding the personality model. The two factors that are relevant to your question are called (1) analytical/tough-minded, and (2) Prosocial/empathetic.
I will now show a few of the questions that load on the two factors:
- I pursue intellectual topics thoroughly and regularly
- Debating is a good way to match my wits with others
- I am intrigued by rules and patterns that govern systems
- I am more analytical and logical than most people
- I am able to solve problems without letting emotion get in the way
- When making a decision, I like to stick to the facts rather than be swayed by people’s feelings
- I like to get to know my friends’ deepest needs and feelings
- I highly value deep emotional intimacy in my relationships
- Regardless of what is logical, I generally listen to my heart when making important decisions
- After watching an emotional film, I often still feel moved by it several hours later
- I am very sensitive to people’s feelings and needs
- I feel emotions more deeply than most people
Another thing you may look at is the empathy and systemizing quotient, see for example (Groen et al, 2015). I believe the idea was originally developed by Simon Baron-Cohen.
This is far from a comprehensive answer, and I don't know how solid and well-established the research it. However, it may be a helpful starting point for you.
Fisher, Island, Rich, Marchalik, Brown (2015). Four broad temperament dimensions: description, convergent validation correlations, and comparison with the Big Five. DOI: 10.3389/fpsyg.2015.01098
Fisher, Rich, Island, Marchalik (2010). The second to fourth digit ratio: A measure of two hormonally-based temperament dimensions. DOI: 10.1016/j.paid.2010.06.027
Brown, Acevedo, Fisher (2013). Neural Correlates of Four Broad Temperament Dimensions: Testing Predictions for a Novel Construct of Personality. DOI: 10.1371/journal.pone.0078734
Groen, Fuermaier, Den Heijer, Tucha, Althaus (2015). The Empathy and Systemizing Quotient: The Psychometric Properties of the Dutch Version and a Review of the Cross-Cultural Stability. DOI: 10.1007/s10803-015-2448-z