What would you say if someone said Big Mac had no personality?

I'm trying to figure out if he really does, or if he formed a personality through our assumptions of him. That's probably why I like writing and reading about him so much.

He's the same as a lot of background characters: authors have to build a personality around what little we know of the character, and for me, that's what I enjoy best about those characters. We can see that Big Macintosh doesn't like speaking a lot, so he could be anything from stoic and thoughtful to introverted and secluded, or perhaps a combination of all and any in between. Such is the beauty of writing.

Does Big Macintosh have no personality? Perhaps to a certain extent, but why should that mean that we can't build on what we know already?

Big Mac does have some personality, even if it's relatively minor.

From what little we know, he has something of a soft side - after all, he has tea parties with a stuffed doll, doesn't he? He's not above pulling a harmless prank on his baby sister, and he can be pretty mean when you get on his bad side (Gabby Gums episode). He also seems to be the kind to lend a hoof when it comes to heavy lifting, as we've seen him do for Twilight when helping repair a bridge and cover the mirror pond.

Sure, there is a lot of blank canvas there, but sometimes that's the fun part of characters. Considering how many people write stories where they make the characters act completely different from how they normally do, I'd say it's a lesser evil.

I would say his major traits would be:

He's very kind, a bit playful and competitive with his sister, big heart, big soft side, always willing to help, really watches out for his family. (And is possibly the smart one of the main family)

2473457 Going with just the show (because I haven't read all the comics), I'm gonna say that Big Macintosh has more personality than a lot of background ponies and even secondary characters. This includes the oddly popular Princess Luna (again going by just the show), who has hardly done anything and people act like she's some tragic figure. She's only tragic in that she was corrupted by evil, but she didn't overcome it on her own, she needed help. I have nothing against Luna, and really I wish the show would do more with her. And in terms of big brothers he's way more defined than Shining Armor, who is pretty much a Gary Stu. What we know of Big Mac through his interactions with others and just on his own: he's hard working, a stallion of few words, patient, apparently good with math (Applejack made reference of "fancy mathematics"), loves his family very much, and rarely loses his temper (but as the Gabby Gums episode shows he can get angry). My favorite moment with him is probably the family reunion episode where he sneakily eats an apple fritter when nopony is looking; it's a moment that shows a playful side and just that he's not always as serious as he looks. And being the biggest and oldest member of the Apple siblings, one does get the impression that he does the most in terms of labor (I'm not saying anything against Applejack, she clearly works her flank off). There's also the Last Roundup episode where his normally stoic nature is broken when he thinks Applejack is never coming home and starts crying, and then his excitement when she gets back. Really that scene was almost a mirror to the Cutie Mark Chronicles episode where Applejack tells the CMC about how she got her cutie mark and ran off to Manehattan. We see Big Mac downtrodden that his younger sister has left the farm and is then excited once she gets back. Honestly,that BBBFF song would fit better with Big Mac and Applejack because we've really known more about the Apple family than we do Twilight and her own. I hear the comics expand on Shining Armor better, but within the show he's not that interesting and was poorly written into the show. Cadence was too, but she's had a bit better development as time went on. So this was a bit rambling, and I wouldn't go into this much detail if I were to answer this under normal circumstances. So yeah, Big Macintosh may not have a larger than life personality, but he has a personality for sure. And really, you don't need all characters in works of fiction to be larger than life. Sometimes you just need a quiet character to go "Eeyup."

2473457 What would you say if someone said Big Mac had no personality?
"Eeyup."

That's not exactly my opinion, but I'd have to say it. Because Big Mac.

The moments when he runs off with Smarty Pants, and when he awkwardly talks with Cherilee about how the CMC are trying to set them up, are very cute. He's got a personality, but we can't be sure yet what it is. There are still a few different possibilities.

Of course I have my own head-canon.