Smart but uneducated people come in a few flavours:
Those who score high on the “Openness” scale tend to be more curious, open to new ideas, and are perceived to be less ignorant than those who are close minded. Smart and educated people notice this.
Those who score low on the “Openness” scale are more close minded, and are more quick to “educate” the expert about how he or she is doing. They seem to know a great deal, but because they lack education they don’t know how to prioritize and organize the information they learn. They “don’t know what they don’t know.” So they get stuck on tangents.

3. Those high on “Agreeableness” may disagree with you privately but won’t make a fuss of it. Those who score low on this trait appear to be blinded by their own stubbornness. They appear to be difficult just for the sake of it, and this doesn’t give others the impression they are intelligent.
Conclusion
If you are uneducated but smart and you find yourself at a party talking with smart and educated people and you want to seem smart, do the following:
Say “okay,” “that’s interesting,” and “I hadn’t considered that.” Let them do the talking.
Listen. Listening makes you seem smart. People like it when you listen, and it makes them think you understand what they are saying, even if you don’t.
Keep your mouth closed. Don’t voice opinions upon which you have no clue if you fear being perceived as stupid.
-Quora
