Nikon D600 D610 - Can choosing a lower resolution improve the noise level?

Nikon D600 D610 -- I realize this is already a very low-noise camera, but I still have this question: Does choosing a lower resolution (before or after shooting) improve the noise level?

- Maximum / native resolution = 6016 x 4016 = 24.3 MP

- Next available lower resolution = 4512 x 3008 = 13.6 MP
- Next available lower resolution = 3936 x 2624 = 10.3 MP
- Next available lower resolution = 3008 x 2008 = 6.0 MP

For example, downsizing from 24 MP to 6 MP could be accomplished by averaging 4 adjacent pixels into a single pixel, (losing resolution but reducing noise).

Is there a setting on the camera that implements such averaging?

If not, can this be done in Light Room or Photoshop or other imaging software?

thanks for your answers

If the lower resolutions were obtained by averaging down the maximum resolution, wouldn't the noise level be decreased?

If the camera does not "average down" to a lower resolution, but merely selects a certain subset of the native resolution pixels

The more pixels you have on any given size of sensor, the smaller the pixels must be. The smaller the pixel, the fewer the number of photons (basic particles of light) will strike the pixel for any given exposure time. Therefore, it's not necessarily the resolution, but the SIZE of the individual pixels that matter. Of course, comparing an 18MP APS-C sensor to a 24MP one means that you're going to have smaller pixels and therefore more noise.
Go to a larger sensor and you can have more pixels while still having large ones too. That's how a 41MP Nokia Lumina smartphone will have such horrible image quality compared to a 40MP Pentax 645D or even a 12MP Sony A7S.

One a photon hits a pixel an electrical charge is created and stored within the pixel. The larger the pixel will gather more photos per exposure thus creating a larger charge. It's that charge that then must be amplified by the computer in order to determine the color/brightness. The lower the charge the more amplification must be applied, and just turning up the volume on a recording to hear sound in the background, you not only amplify the signal, but you also amplify the noise generated by the recording system itself. That's why you will hear a lot of his and/or hum on the sound recording - especially if recorded and played back on low-end equipment. Just like the poor recording, a strong signal captured by large pixels will have less inherent noise because it's not be amplified as much. Factor in the quality of the electronics (found in high end cameras) and you'll have even less noise due to the cleaner signal from the better electronics within the camera.

All of this is why lowering the resolution of any camera will have no affect on the noise level. It's not the number of pixels, but the size of the pixel that matters.

Here's a link that compares sensors: http://www.digicamdb.com/

When you down-sample an image (reduce the size), you will have averaging which will reduce noise. It won't be much unless you really make the image pretty small, like under 800 pixels.

The more information (data) that is saved by your camera, the better the image quality. This includes colour depth, dynamic range as well as low noise at high ISO settings. If you are shooting in low light, you can turn on the NR (noise reduction) for low light and if your exposures are longer than one second, turn on the long exposure NR feature as well.

The fewer pixels you use, the lower the image resolution will be so noise will be more apparent and the colour depth and dynamic range of the image will suffer

Shoot in RAW and then use the noise reduction in LR CC to make any small corrections. The more you correct, the less detail will appear in the final image