How do citizens form and update their opinion about political topics? While the literature generally agrees that new information has to be received and accepted to affect political preferences, research on the exact mechanism of information acquisition and the condition under which this process is more or less likely remains scarce. This is what we tackle in this paper by paying special attention to the active search for information as well as to the source of it. We designed an experiment that isolates the process of information acquisition and especially differentiates between two mechanisms that could drive the results by Vössing and Weber (2019): larger salience of the attitude or information updating, i.e. adapting attitudes. Importantly, we also take the source of information (experts vs citizens) into account. To do so we select two issues (economic inequality and climate change) with varying salience at the macro-level but also between individuals. By studying the influence of an active search for two new topics and by leveraging several countries in our research, we provide a robust basis for how the process of information acquisition shapes attitudes.