A downloadable mod

This is a mod for The Sims 4.

Last updated: v9, 29 August 2017
Working for The Sims 4 v1.36.99 / The Cats and Dogs Patch

What it does
Sims' moods will have inertia. Moods become more resistant to change, and can last beyond the original moodlets that caused them. It can now take a sustained effort and multiple points of another emotion to change their mood.

Why would you want this?
In the base game, sims' emotions typically flip about on four hour timers like little clockwork goldfish. Nothing affects their mood for long, and once you're familiar with the game, it's not difficult to get the few points needed to change their mood when you want to.

With this mod, once something happens to put a sim in a mood, that mood will likely last at least as long as the effects of the thing that caused the mood, and even after that it will take time and effort to put them in a different frame of mind. The aim is for this to make emotions feel a little more meaningful, to make your sims feel a little more human, and to make managing their mood take a little more planning and be a little more challenging.

Emotional Inertia in detail
When your sim enters a mood, they will be given a moodlet for that mood, the strength of which depends on their age and whether the mood is positive or negative. When that moodlet's timer runs out, it will be replaced by a weaker moodlet.

After your sim enters another mood, the inertia moodlet from the previous mood will be removed.

There are three levels of inertia moodlet:

  • Strong: +3 - lasts 8 hours, followed by
  • Medium: +2 - lasts 8 hours, followed by
  • Fragile: +1

The +1 level has no visible duration but will rarely last long at all because of the way the game handles mood changes. Once a +1 inertia moodlet is the only thing left keeping a sim in a mood, it will be overcome by any more recent +1 moodlet for any other emotion.

Starting inertia levels:

  • Toddlers: no inertia.
    The emotional balance for toddlers is pretty good, so I don't mess with it.
  • Children: +1 for positive moods, +2 for negative moods.
    Children will find it easier to bounce back and change in mood than adults.
  • Teens to Elders: +2 for positive moods, +3 for negative moods.
    These sims are more emotionally stable.


  • The happy and uncomfortable moods get no inertia.
    You won't get sims stuck as 'uncomfortable' hours after needing a shower.
  • Entering the uncomfortable mood does not remove inertia moodlets from other negative moods.
    Your sim can go right back to feeling sad after they've dealt with their bladder emergency.
  • Unflirty adult sims get only +1 flirty inertia.
    It should be easy to bring them out of the flirty mood after the moodlet that put them in it has expired.
  • Non-currently-played sims: +1 for positive moods, +2 for negative moods.
    NPCs get weaker inertia so that party goals about changing guests' moods aren't totally impossible.

The amount of points needed to enter the higher intensity levels of an emotion has been raised to allow for the inertia moodlets.

Support and updates
To keep informed of updates to my mods, click the follow button on patreon for email alerts. You can also follow me on tumblr and twitter.

If you like this mod and would like to support my work on it and other mods like it, please consider supporting me through my patreon page.

Become a patron

Tips for playing
With this mod, managing your sims' moods can become challenging.

Falling into a negative mood is a meaningful problem. If it happens, your sim will likely only be able to be pulled out of it after the moodlet that caused the mood change expires. After that, you'll have to find multiple sources of +happy to overcome the strong inertia for a negative mood. A drink, a nice meal, a deep connection with another sim, or a good workout can be good places to start.

But you'll also need to think about what positive mood they'll end up in when they finally overcome their bad mood. Because if it's not one you wanted them to be in, you might have another problem.

With adults, even an undesired positive mood can take some planning to overcome. To beat a +2 positive inertia moodlet, you'll need either a +2 moodlet or three different +1 moodlets for the positive mood you want them to have. Learning the different ways your sim can gain moodlets for the emotions they want will be important if you want to have control over their mood. Start with viewing an emotional artwork, doing some research on the computer, or taking a particular kind of shower.

Or you can just let their moods flow where they will, and follow your sim's lead for their desires in life.

How this mod came about
I started this as a project to learn to use Zerbu's Mod Constructor tool. Zerbu's excellent old Lingering Emotions mod was no longer working for me, and I missed it, so I started out by trying to recreate its effects. The mod has developed a lot since then, and I feel it has enough differences now from Zerbu's original mod to be distinct and worth sharing.

Known issues

  • Emotion reducing interactions only reduce moodlets that were present when the interaction started. This means if a strong emotional inertia moodlet transitions to a weaker one while your sim is performing an emotion reducing interaction, the new moodlet won't be reduced unless you start the interaction again.

Recommended mods to go with this

  • Uncomfortable Overhaul
    Emotional Inertia was made assuming a mod like this will also be installed. With uncomfortable moodlets sometimes boosting other negative moods, negative emotions can be more of a threat, making emotional inertia more interesting.
  • No Happy Environment Moodlets
    With permanent happy moodlets around, emotional inertia can make it too easy to stay in a positive mood. Disable happy moodlets from decorations for a better balance between positive and negative moods.
  • Variable Emotional Traits
    Random strength moodlets from emotional traits can give another little push towards gloomy and hot-headed sims sometimes feeling sad or angry.


  • This mod was inspired by Zerbu's Lingering Emotions mod, which is no longer available
  • This mod was made with Zerbu's Mod Constructor v2
  • I am a bit of a fan of Zerbu's work, perhaps you can tell
  • Thanks to Sjofn, Dan Lawrence, Apex Pecoris, and Loofofbread for testing and reporting bugs.


  • v9, 29 August 2017: A big update!
    • The filename has changed with this version, so you should delete any previous version of the mod before updating!
    • The mod no longer includes Zerbu's Uncomfortable Boosts mod - you can now install my new Uncomfortable Overhaul separately to replace it, with no conflicts.
    • The mod now uses no overrides, so should conflict with no other mods.
    • The inertia moodlets are now applied to all sims, including NPCs. NPCs get weaker inertia than played sims.
    • Played teens now get regular +2 positive inertia again.
    • +3 and +2 inertia moodlets now last 8 hours, down from 10 hours. This feels like the level where emotion-reducing interactions feel useful.
    • +1 inertia moodlets no longer show their duration. I thought this might help lead players to the conclusion that waiting them out is not the best approach.
    • +2 tense inertia given to children and NPCs now has the right emotion tag. It should now be reducible by tense-reducing interactions. Thanks to Apex Pecoris for the bug report.
    • The happy and uncomfortable moods now get no inertia by default again.
    • Becoming uncomfortable will no longer remove inertia moodlets for other negative moods. This is to support my new mod Uncomfortable Overhaul
    • Emotional Inertia is now ready for and compatible with my upcoming Happiness Overhaul mod. 
  • v6, 04 June 2017: 
    • Children now get weaker inertia. 
    • Teens now get weaker positive inertia. 
    • Non-currently-played sims now get weaker inertia. 
    • Happy and uncomfortable moods now get only +1 inertia. 
    • Unflirty adults now get weaker flirty inertia.
  • v5, 11 March 2017: The +2 stage of positive emotional inertia now lasts 10 hours instead of 15. The happy and uncomfortable emotions now have inertia as well. Inertia moodlets from the previous emotion are now removed instantly when an inertia moodlet for a new emotion is given.
  • v4, 02 March 2017: Initial public release.

This mod overrides no files, and should not conflict with any other mod.

More information

Published Jun 06, 2017

Install instructions

Extract the contents of the zip file into your 'Documents/Electronic Arts/The Sims 4/Mods' folder.

If you are upgrading from a version of Emotional Inertia older than v9, first delete the older file from your mods folder.


roBurky - EmotionalInertia.zip 91 kB

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