Learn Hardcore Spanish (Latin America): En la universidad mi materia favorita es psicología, aunque mi promedio es mejor en matemáticas. - At the university my favorite subject is psychology, although my average is better in math.

En la universidad ≈ At university / In college (in general, not one specific building).
Saying En universidad is ungrammatical in this context.

Spanish uses the article where English often omits it with institutions:

en la escuela = at school
en la universidad = at university / in college
en el trabajo = at work

Do I need a comma after “En la universidad”?

You can put a comma, but you don’t have to. Both are acceptable:

En la universidad, mi materia favorita es psicología…
En la universidad mi materia favorita es psicología…

The comma is often added because “En la universidad” works as an introductory phrase (a setting in time/place). Many writers would include it, but in everyday writing it’s also common to leave it out. It’s a stylistic choice here, not a grammar error.

What does “materia” mean here, and how is it different from other words like “asignatura” or “clase”?

In this sentence, materia means school subject (e.g., math, history, psychology).

In Latin America, materia is the most common word for an academic subject.
In Spain, people more often say asignatura for “subject.”

Other related words:

clase = the class session or the course (can mean “lesson” or “class you attend”)
curso = course, school year, or a more formal course of study

So:

mi materia favorita es psicología ≈ my favorite subject is psychology
mi asignatura favorita… (more common phrase in Spain)

Why is it “mi materia favorita” and not “mi favorita materia”?

In Spanish, most adjectives go after the noun:

materia favorita = literally “subject favorite”

So the normal order is:

mi materia favorita (my favorite subject)
NOT ✗ mi favorita materia

Spanish does sometimes put certain adjectives before the noun (e.g., buena idea, gran película), but favorita strongly prefers to come after the noun in this kind of phrase.

Why is “psicología” not capitalized, but “matemáticas” also isn’t capitalized? In English we’d write Psychology and Math for a class.

In Spanish, names of school subjects and academic disciplines are not capitalized unless they start a sentence:

psicología
matemáticas
historia, biología, inglés

So:

Mi materia favorita es psicología.
Estudio Matemáticas. (capital M only because it’s the first word of the sentence, not because it’s a subject)

Why does “psicología” have an accent on the í?

Spanish accent marks show where the stress (spoken emphasis) falls when it doesn’t follow the normal rules.

psicologia (without accent) would normally be stressed on -lo-: psi-co-LO-gia.
But we actually pronounce it psi-co-lo-GÍ-a.

To mark this irregular stress, Spanish writes psicología with an accent on í so you know to stress -gí-: psi-co-lo-GÍ-a.

Why is “matemáticas” plural?

In Spanish, many school subjects are grammatically plural, even though in English we often use a singular form:

las matemáticas = mathematics / math
las ciencias = science (as a school subject)
las finanzas = finance(s)

So you say:

Soy mejor en matemáticas. = I’m better at math.

It’s just a conventional plural form; it doesn’t mean there are “many maths” in everyday usage.

Why is it “es psicología” and not “está psicología”?

Spanish uses ser (es) for essential characteristics, identity, and classification. Here, you’re stating what your favorite subject is (a more permanent description of preference):

Mi materia favorita es psicología.
→ My favorite subject is psychology.

You would use estar for temporary states, locations, or conditions:

La clase de psicología está en el edificio B.
→ The psychology class is in building B. (location)

What does “aunque” mean here, and how is it different from “pero”?

Aunque means although / even though, and it introduces a contrast that feels a bit like a concession:

…aunque mi promedio es mejor en matemáticas.
→ “…although my GPA/average is better in math.”

Pero means but, and is a more neutral contrast:

…pero mi promedio es mejor en matemáticas.

Both are possible, but:

aunque suggests: this is somewhat surprising given what I just said.
pero just adds contrast without that “in spite of” feeling.

So aunque fits nicely because it implies: Even though psychology is my favorite, I actually do better in math.

What exactly does “promedio” mean in this context?

Promedio literally means average. In school/university contexts in Latin America, promedio usually refers to your grade average (GPA, overall marks):

mi promedio es mejor en matemáticas
→ my average/grades are better in math

It doesn’t mean “medium” here; it specifically means the average score you get in that subject.

Why is it “mejor en matemáticas” and not “mejor que en matemáticas”?

Here mejor en matemáticas means “better in math” → I perform better when it comes to math.

You would use que if you are directly comparing two things:

Mi promedio es mejor en matemáticas que en psicología.
→ My average is better in math than in psychology.

In your original sentence, the comparison with psychology is already implied by context (“my favorite” vs “my average is better in…”), so saying:

…mi promedio es mejor en matemáticas.

is natural and doesn’t need que explicitly.

Why is it “mi promedio es mejor en matemáticas” and not “tengo un mejor promedio en matemáticas”?

Both are correct, but they sound slightly different:

Mi promedio es mejor en matemáticas.
→ More direct, simple: My average is better in math.
Tengo un mejor promedio en matemáticas.
→ Literally I have a better average in math.
Sounds a bit more like you’re explicitly comparing two averages (e.g., this semester vs last semester, or math vs another subject).

In everyday speech, “mi promedio es mejor en…” is shorter and very natural.

Could I say “psicología es mi materia favorita” instead? Is that wrong?

You can say:

Psicología es mi materia favorita.

It’s grammatically correct. The difference is mostly emphasis:

Mi materia favorita es psicología.
→ Slightly emphasizes “my favorite subject” as the topic.
Psicología es mi materia favorita.
→ Slightly emphasizes “psychology” as the topic.

Both are natural; the original version is just a very common pattern for expressing preferences.