Do we look that much alike? My son's face can open my iPhone

When my 10-year-old son picked up my iPhone last month, he had no idea he was about to make a discovery.  Before he had a chance to enter the passcode, my Face ID welcomed him in.

For those unfamiliar with the Apple iPhone, Face ID is a facial recognition security feature that gives the phone's owner access to their device without having to enter a passcode. Face ID was introduced by Apple to replace the previous biometric security feature using fingerprints.

That's why I was shocked when my son's face gave him access to my phone. 

I initially assumed it was a random one-time occurrence or something was wrong with my Face ID. However, neither would prove true. My son's unfettered access continues, and trials with my other sons, non-relatives and friends showed my Face ID was functioning well and otherwise kept my phone secure.

But it did lead me to wonder about whether other families were making similar discoveries. I spoke with many people within my social and professional networks and it turns out that my son and I aren't in a unique situation.

When the topic came up in our newsroom, CBC science specialist Darius Mahdavi said he and his sister Persia can also open each other's phones. 

Persia Mahdavi said she found the situation amusing.

"I picked up Darius's phone and was going to enter the passcode, when the Face ID unlocked the phone. I laughed very hard, called everyone over, then tried it a bunch more times, and it kept working for me."

Persia uses her phone for Apple Pay and to log into other apps on her phone, but said she's not worried.

"I thought it was hilarious. I showed everybody. Darius was less amused. His face opened my phone inconsistently, but I could open his phone every time."

She said even though she knew they looked alike, "I didn't think we looked that alike."

However, in her family, it's not just Persia and brother Darius who can open another person's phone through Face ID — their dad and his brother can do it to each other as well. 

According to the Apple website, the probability that a random person in the population could look at your iPhone or iPad Pro and unlock it using Face ID is less than 1 in 1,000,000.

However, it goes on to state "the statistical probability is higher — and further increased if using Face ID with a mask — for twins and siblings that look like you, and among children under the age of 13, because their distinct facial features might not have fully developed."