A natural experiment[0] done on female iPhone users from 2007-2011 found that the iPhone accounted for a 33-52% decline in fertility rates among women aged 15-44.

The experiment used data from ATT users, the exclusive carrier of the iPhone for the given years.

This correlates with another study[1] that found that starting in 2007 teens shifted their socializing to the smartphone. This led to a large reduction in teen fertility, as they would spend more time communicating digitally rather than in person.

Sometimes you're working on a project that has a different indentation level for JavaScript. You can use this:

(setq-default js-indent-level 2)

We can use the following commands to reposition the text around the cursor:

• zz - move text to middle of screen
• zt - move text to top of screen
• zb - move text to bottom of screen

To play a sound via the terminal we can use afplay:

afplay -t 0.25 "/System/Library/Sounds/Blow.aiff"

To send notifications on MacOS we can use osascript:

osascript -e 'display notification "Your message" with title "The Title"'