Why can we not just take the Comic Sans serious? Typology makes and investigates the teorie that typefaces have personalities and they can be compared with human personalities.
Typefaces communicate because of semantic associations. Every association will be caused by the perception of their the form, weight, size and color, which will be directly connected to a engraved memory or the personal context of the observer, creating a visual atmosphere. The emotional and cognitive correlation of the formal characteristics can only be analyzed through the comparation between typefaces of different classifications. The qualitatively contrast between the types can be described out from the impact they have.

"A recent study shows unobjectively that the Bellevue is playful (88%), the Futura however counts for factual (52%)."
Ernst , Wechselwirkung

The semantic associations depend on several formal factors such as form, white spaces, contrast, finials (serif/sans serif) and also contextual factors like perceptive anticipations, theme, complexity of the reading levels, reading physiology (legibility), rythm, historical and regional references. E.g.:The emphasising of the horizontal forms have a dynamic effect meanwhile open forms are more humanly-a-like and warm in opposite to the satic and closed ones, which tend to be cold, angular forms are hard, emphasized ascenders and descenders are elegant, narrowed white spaces are muffled, soft finials are relaxed and low contrast is austere and sober.
That's why a font (if well selected) not only influences but also interpretates the symbolic behind the text (always depending on the perception and understanding of the typographer). In spite of the fact that some fonts are in trend (because of the temporal context of the design process), fonts should be not chosen by the design tendences of the moment, but specifically for the meanings and concepts that sould be delivered. Nevertheless that the study and analysis of perception is not always objective and most of the time ambiguos to prove.

"Because it should be not forgotten, that exciting is sometimes the unexpected, the unknown, the extraordinary. An sometimes it must not be a extraordinary font, it can be a familiar font in a unusual context.
Stephanie & Ralf de Jong, Schriftwechsel

Sources:
* Stephanie & Ralf de Jong | Schriftwechsel
*Frossman & de Jong | Detailtypografie
*Ernst | Wechselwirkung
*Kapr | Gestalt und Funktion
* Which typeface for which use? (german)
* How every typeface has an emotional life and personality
* The definitive guide to typography in branding
* Typeface classification (german)
* The principles of the new typography by Jan Tschichold
* Thinking with type

*Connections between semantic associations. Click on the link about the graph.