Learn Spanish (Latin America): El psicólogo ha dicho que hablar es lo normal. - The psychologist has said that talking is the normal thing.

Lo is the neuter article. When you put lo in front of a singular, masculine adjective like normal, it turns the adjective into an abstract concept or idea. Instead of describing a specific noun, lo normal translates to "the normal thing" or "what is normal".

Why does the sentence use hablar (to talk) when the English translation says "talking"?

In English, we often use the "-ing" form of a verb as a subject or a noun, like "talking". In Spanish, you always use the infinitive (the basic, unconjugated) form of the verb to do this. So here, hablar acts as the noun "talking".

I know ha dicho means "has said", but why isn't the word for said decido?

The phrase ha dicho is the present perfect tense, built with the helper verb haber (has) plus a past participle. The verb decir (to say) has a completely irregular past participle, which is dicho. It is a very common exception that you just have to memorize.

Do you pronounce the 'p' at the beginning of psicólogo?

In everyday Latin American Spanish, the 'p' is silent in words that start with 'ps' like psicólogo (psychologist) and psicología (psychology). You just pronounce it starting with the 's' sound: "si-có-lo-go".