I have a question regarding the analysis/interpretation of a significant interaction between a continuous variable and a categorical variable, which seems pretty easy but I just don't understand it completely.
This is my main model: modelExp2 <- lm(Prosociality ~ fCondition + Neuroticism + Extraversion + Openness + Agreeableness + Conscientiousness + fCondition:Neuroticism + fCondition:Extraversion + fCondition:Openness + fCondition:Agreeableness + fCondition:Conscientiousness, data=DataExp2)
I found that the interaction fCondition:Neuroticism and the interaction fCondition:Extraversion are significant. fCondition is the condition, with 2 levels (imitation or no-imitation). Neuroticism and Extraversion are both continuous predictors. In order to analyse these effects further my teacher suggested to plot these effects, but I assume that I also need to know the significance of this? That is, in my report I should also write down the significance of Neuroticism on the dependent variable for each of the two levels of Condition, right? How can I do this? The plot gives me an idea about the direction of the effect per level, but it does not tell me anything about the significance of this per level.